I picked three of your last games and reviewed them to find a common theme. I found a couple.
1. You should solidify your knowledge about basic opening and middlegame principles.
a) When you split a side, you should preferably do so with having two possibilities to make a base (Miai). A common base is a two-point extension along the third line.
b) You should defend the weaker poisition not the stronger one. In most cases the weaker position is the one with less of your stones around.
c) Don't fixate only on territory. Yours or your opponents. First comes save groups or attacking weak groups!
d) Don't hurt your own weak stones by pushing your opponent towards them or by making him unnecessarily stronger.
e) If you want to attack your opponent, you have to have strong positions. Otherwise your opponent can play forcing moves threatening to kill or cut you and gain an advantage in the fight.
f) Don't let your opponent enclose you for no good reason - the center is important! You have to make small live while your opponent gets massive thickness, which can influence the whole game.
g) Deny your opponent an easy base whenever you can.
After that and only here comes reading ability. It is really a minor part in the games I saw.
Here are the games with my comments. Beware I'm also a weak Kyu and prone to make mistakes ; ) Maybe stronger player will comment, too.
(;SZ[19]FF[4]US[XuanXuanGo]PB[Serch]PW[hailthorn]BR[8k]WR[7k]DT[2012-06-11]PC[The KGS Go Server at http://www.gokgs.com/]
RE[B+Resign]RU[Japanese]OT[5x30 byo-yomi]TM[1800]KM[0.5];B[dp];W[pd]C[Serch [8k]: hola gg
];B[dd]C[hailthorn [7k]: Howdy, good game
];W[pp];B[nq];W[qn];B[pr];W[qq];B[kq];W[cf]C[White does not usually approach here. The reason is, a black pincer would work well together with the bottom left Hoshi and even could form a framework here.
Still, it's completely possible to play here if you are aware of that.];B[fd];W[ci]C[That move is a bit odd. Sure, you are making a perfect extension and a good base for now, but a Black move at 'A' will make you overconcentrated the moment you extend to 'B'.
'C' is the usual move in this situation. If you want to extend down the left side 'D' is a possibility. But it's more common in a handicap game since it's a light shape which can easily be attacked.]
LB[bd:C][ce:A][df:B][ck:D];B[ce]C[This Black move hits the spot.];W[cl]C[This move secures your group. If Black had the chance to play 'A', you would be in trouble.
Still, C14 (marked) grows weak, if you defend, C11 is too close and Black's top left corner is getting big. Your play (three moves) on the left side was not very efficient.]
TR[cf]LB[ck:A];B[cn]C[This move is not so big and in my opinion not even urgent. White has no good follow-up against the Hoshi for the moment.
A black play at 'A' is huge and would already bring Black in a leading position, I think.]
LB[bf:A];W[cq]C[Way too early. See variation at move 21.];B[dq];W[dr];B[er];W[bo](;B[cr];W[bn]
;B[cp];W[bq];B[bp];W[br](;B[cs]C[See variation.];W[ap];B[bs];W[aq];B[bm];W[cm];B[co];W[bl];B[df]
C['A' is better here. Secures the corner, takes more territory.]LB[bf:A];W[cg];B[dg]C[Pushing from behind. Black does not gain much.]
;W[nc];B[qf];W[kc]C[Wrong direction. 'A' is close to the only move here. Takes a good amount of territory and denies Black an easy base.
Attacking with White 'B', Black 'C' and White 'D' is also possible.]LB[rd:A][qe:B][pf:C][pi:D]
;B[rd];W[qk]C[Again wrong direction. 'A' is huge in terms off territory.
White 'B' is a option, too. But your move misses the scene of action, in my opinion. It defends a strong group.]
LB[qc:A][qg:B];B[ic];W[cc]C[Huge. This is the reason, why Black should have played 'A' instead of the marked move. 'A' would have defended the corner.]
TR[df]LB[bf:A];B[dc];W[be];B[bd];W[cd];B[de];W[bc];B[bf];W[ad];B[bg]C[Bad move. Does not achieve anything. Black could cut at 'A' instead, which is pretty big but the loss of the corner is bigger in my opinion.]
LB[ch:A];W[ch];B[bh];W[bi];B[cb];W[bb];B[ca];W[ba];B[eb](;W[qh]C['A' is still bigger than this and even has more implications on the black group.
See variation.]LB[qc:A];B[qc];W[pc];B[pb];W[ob];B[pa];W[oa];B[rb];W[ra]C[There is no way to kill this group right now. This move loses a Ko threat.]
;B[qb];W[no]C[Your stones are all on the third line, so you can't hope to make a framework yourself. If you want to reduce Black then 'A' is the usual choice.]
LB[jp:A];B[pg]C[Bad move. Defends a strong group while attacking a likewise strong group.];W[ph]
;B[oh];W[oi];B[nh];W[ni];B[mi];W[mh]C[Unecessarily aggressive. 'A' is fine. You build a framework out of nothing. He just places stones on dame points.]
LB[mj:A];B[mg];W[lh];B[li];W[lg];B[mf];W[lf];B[me];W[le];B[md];W[mc]C[Now your cut weakend your own group and you did not gain anything.]
;B[ld];W[kd];B[ke];W[je]C[If you can't capture this stone (and you really can't if I see this correctly [at least cleanly]) then don't take away your own liberties. Just jumping to 'A', threatening to capture and then 'B' is okay.]
LB[jg:A][ki:B];B[kf];W[kg];B[jf];W[jg];B[if];W[ki];B[kj];W[ji];B[jj];W[lj]C[Again, too aggressive. Don't attack when you are weak! 'A' is solid, 'B' gets tricky and tries to exploit (if Black cuts at 'A', you use the Driving-Tesuji) the Aji around 'C' and 'D' (when White has stones on the marked places).]
TR[lc][hg][ig]LB[he:D][og:C][ii:A][ij:B];B[mj];W[lk];B[mk];W[ll](;B[pi]C[See variation. END OF COMMENTS.]
;W[pj];B[ml]C[stalkor [4k?]: move 110, 3 minutes spend = 55 moves /180 secs = 2.9 secs PER MOVE]
;W[ij];B[jk];W[ii];B[lm];W[kl];B[jm];W[jl];B[ik];W[il];B[hk];W[hl];B[gl];W[mm];B[nm];W[mn];B[ol]
;W[km];B[ln];W[kn];B[lo];W[ko];B[nn];W[mo];B[lp];W[oo];B[on];W[pm];B[pn];W[qo];B[pl];W[qm];B[ql]
;W[rl];B[rk];W[rm];B[qj];W[qi];B[pk];W[rj];B[oj];W[qk];B[nj];W[pi];B[qj];W[ri];B[sk];W[qk];B[hi]
;W[hj]C[stalkor [4k?]: wut?
];B[gj]C[stalkor [4k?]: TERRIBLE!:D
];W[qj];B[ig];W[hh];B[jh];W[gi];B[kh];W[gm];B[fl];W[fm];B[fj];W[fi];B[ei];W[eh];B[dh];W[ej]
;B[di];W[dj];B[fh];W[gh];B[fg];W[fk];B[gk];W[el];B[ek];W[kk];B[cj];W[fk];B[bj];W[jp];B[dk];W[fj]
;B[ck];W[dl];B[jq];W[lc];B[jd];W[jc];B[id];W[nd];B[ne];W[oe];B[of];W[hp];B[hq];W[gq];B[hr];W[fp]
;B[gr];W[fq];B[fr];W[eo];B[en];W[fn];B[ip];W[io];B[iq];W[dn];B[ho];W[gp];B[in];W[jo];B[ep];W[kp]
;B[mq];W[qr];B[ps];W[qs];B[pq];W[oq];B[or];W[op];B[nr];W[rg];B[rf];W[sj];B[pe];W[od];B[qd];W[ib]
;B[hb];W[ia];B[ha];W[jb];B[gc];W[gg];B[gf];W[ff];B[eg];W[hf];B[ge];W[hg];B[he];W[om];B[sg];W[sh]
;B[qg];W[sf];B[se];W[sg];B[rp];W[qp];B[gn];W[fo];B[af];W[ae];B[ai];W[ak];B[bk];W[al];B[ds];W[po]
;B[nl];W[do];B[ar];W[as];B[ao];W[an];B[ar];W[mp];B[lq];W[as];B[ac]C[Serch [8k]: thx
])(;B[ii]C[Very painful. Might even be game over.]TR[ji][ki]))(;W[qc];B[qi];W[rh];B[ri];W[qe]
;B[re];W[qg]C[I think something along these lines.]))(;B[ds];W[ap];B[ar]C[I think White has a really hard time here. Your attack backfires.]
))(;B[bn];W[co];B[do];W[cr];B[dn];W[ar];B[fq]C[Imagine, it ends like this. For the sake of the argument: You will live in the corner (but you probably could also die locally if I'm not mistaken).
Your 'A'-group becomes weaker because Black is so strong nearby and 'B' is a perfect extension from Black's wall. All you got are a couple of points in the corner. Black's advantage just got even bigger, the game like this is extremely difficult for White.]
LB[ci:A][kq:B]))
(;SZ[19]FF[4]US[XuanXuanGo]PB[hailthorn]PW[Nathan]BR[7k]WR[6k]DT[2012-06-14]PC[The KGS Go Server at http://www.gokgs.com/]
RE[W+Resign]RU[Japanese]OT[5x40 byo-yomi]TM[2400]KM[6.5]C[Nathan [6k]: have a good game
hailthorn [7k]: Hello, good game
hailthorn [7k]: L19 Tournament
];B[pd];W[dp];B[pp];W[dd]C[hailthorn [7k]: Welcome back
Nathan [6k]: i am worried about my internet
hailthorn [7k]: Well, what should we do then?
];B[fc];W[cf];B[jd];W[qg]C[Very unusual move. 'A' is very big for Black.]LB[qe:A];B[qe];W[qn]
C[Nathan [6k]: Hope that it works
];B[ql]C[Maybe not the ideal choice when White has the marked stone, you end up being severely attacked. If you want to split then a fourth line pincer might be better.
There is nothing wrong with 'A', too.]TR[qg]LB[nq:A];W[on];B[qi];W[np]C[Very painful for Black!]
;B[nq];W[oq];B[op];W[pq];B[no]C['A' is the shape move. Still the fight is tough for Black.]
LB[qq:A];W[mp];B[oo];W[qq];B[qp];W[mo];B[nn];W[pk];B[pl];W[ok]MN[1];B[ol]C[Letting White cut you at 'A' is again very painful. Actually you have to play there yourself but then your lower group will get attacked again.
Although you still can connect at 'B' the result is horrible for Black.]LB[qk:A][rn:B];W[qk]
C[Horrible result for Black. Next time, don't let White play the marked stone.]TR[np];B[pg]
C[Wrong side, 'A' is better.
See variation.]LB[rg:A](;W[qh];B[ph];W[pi];B[pj];W[oi](;B[oj]C[Read! See variation.];W[qj]
;B[qf];W[ri];B[cn]C[Good! Right side.];W[dn];B[co]C[Unusual. 'A' is more common and might be better in this situation.]
LB[dm:A];W[do];B[cp];W[cq];B[bq];W[dq];B[cm]C[Black has not the best shape. 'A' is HUGE endgame.]
LB[br:A];W[ip];B[nc]C[Too slow! Black would welcome White to invade there. The fight would be entirely favourable for Black!
'A' is bigger but I think 'B' is urgent and has the nice follow-up at 'C'.]LB[fe:A][mn:B][kp:C]
;W[mn];B[nm]C[Painful to answer here. White enlarges his Moyo in Sente.];W[db];B[cc]C[Looks very crude!
'A' is normal to cover the weakness at 'B'. Later you have good endgame at 'C' to produce some Aji in the corner.
You have to evaluate some things here: Imagine you live in the corner. How much points do you get? And how much damage will White inflict to your marked stones due to his ensuing incredibly strong position?]
TR[fc][jd]LB[fe:A][hc:B][eb:C];W[dc];B[be];W[bf];B[cb]C[Locally 1-2-3 kills, I think.]LB[ce:1][bd:2][bb:3]
;W[bd];B[ce];W[de];B[cd];W[ca];B[ba];W[da];B[bc]C[Nathan [6k]: woops
];W[jc];B[ic];W[id](;B[hd]C[See variation.];W[ie];B[he];W[hc](;B[gc]C[See variation.];W[ib]
;B[gf]C[Slow and heavy. You will be an easy target! I would probe the Ko first ('A') to see what White does. If he connects you can think about cutting at 'B' or peep at 'C' to make shape in the center. White has to make life for his wall, too.
Despite that you could have played differently, look at this result in comparison to what you got in the corner. White became very strong and attacked, now you have running group and your top area is completely destroyed.
I think, living in the corner was too early here.]LB[hb:A][df:B][ef:C];W[fe];B[ge]C[Black is really heavy now. If you play with a lot of opponent stones nearby you must make sacrifices.]
;W[ff];B[df]C[Read!];W[dg];B[fg];W[gg];B[hg];W[gh];B[hh];W[fh];B[kb]C[Playing near thickness? Good endgame but this totally misses the point that you are under attack right now! 'A' is very good for Black.]
LB[if:A];W[if];B[hf];W[kd];B[ii]C[Running away without making a point or launching an attack. Before you get in this situation, think about sacrifing the stones. In a lot of situations it's better.]
;W[ck];B[dk];W[cj];B[dj]C[Pushing from behind is mostly bad. END OF COMMENTS.];W[el];B[dl];W[il]
;B[em];W[en];B[fl];W[fm];B[ek];W[gm];B[nr];W[or];B[lr];W[jr];B[kq];W[ko];B[jq];W[iq];B[qs];W[os]
;B[ns];W[rq];B[rp];W[sq];B[rs];W[sp];B[ro];W[so];B[rn];W[kr];B[lq];W[mq];B[mr];W[jp];B[sn];W[kp]
;B[ks];W[ir];B[ll];W[nj]C[hailthorn [7k]: ty
Nathan [6k]: thanks
])(;B[ib]C[Only move in my opinion. Top right is bigger.];W[gc];B[kc];W[je];B[jb]C[Now White has to defend his own stones.]
))(;B[hc]C[Strongest resistance, I think. 'A' and 'B' Miai.]LB[ie:A][kc:B]))(;B[qj]C[Possibly the only move. Might get ugly.]
))(;W[ph];B[qh];W[pf];B[qf];W[og];B[rg]C[The Ponnuki is worth more than Black's second line territory and helps the three white stones.]
))
(;SZ[19]FF[4]US[XuanXuanGo]PB[OceanMon]PW[hailthorn]BR[4k]WR[7k]DT[2012-06-08]PC[The KGS Go Server at http://www.gokgs.com/]
RE[B+Resign]RU[Japanese]OT[25/600 Canadian]TM[2700]KM[6.5]C[OceanMon [4k]: hi have a good game
];B[pd]C[hailthorn [7k]: Hello, good game
OceanMon [4k]: where do you live?
];W[dp];B[pp]C[hailthorn [7k]: Virginia
];W[dd];B[fp];W[fq]C['A' is more common, but your move is okay, too.]LB[dn:A];B[gq];W[eq]
;B[hp];W[dn];B[lq]C[This result is very good for White. The corner is huge and pretty safe.]
;W[nc]C[Splitting at 'A' is good idea, too.]LB[qj:A];B[qf];W[jd];B[ci];W[cl]C[This move is a bit passiv. It defends your corner, where you have already four stones in place. Defending your top corner (around 'A') might be bigger because it leads to Black approaching your strong position in the bottom left.]
LB[cg:A];B[cf];W[fc]C[Playing at 'A' makes Black overconcentrated, I'd opt for that here.]LB[ce:A]
;B[bd];W[qj]C[This move is not so good. You can only make a base around 'A' but when Black approaches from this side, you will have to run. If you split a side, always make sure you have two ways to make a base! (Here at 'B' for instance.)]
LB[qm:A][qk:B];B[ql];W[qh];B[ld];W[ne]C[Fighting spirit! But keep in mind that your A-group is not safe!]
LB[qh:A];B[of];W[le];B[oi];W[oj];B[pk]C[Bad move. Broken Keima, you remember ; )]TR[oi][pk]
;W[pj];B[nl];W[pm]C[Bad, too. You had a nice move at 'A' before this. After this move, Black is strengthend and it did not help you.]
LB[rl:A];B[pl];W[om]C[Family feud? You are hurting your own stones. Instead of rescuing your first weak group, you are creating another.]
;B[nj];W[oh];B[nh];W[pi];B[ni];W[og];B[pg];W[qg];B[ng];W[rf];B[qe];W[re];B[rd];W[ri];B[nm];W[qo]
;B[qp];W[oo];B[mo];W[op];B[oq];W[nq];B[or];W[mp];B[lp];W[nr];B[qr];W[rm];B[po];W[rl];B[qm];W[qn]
;B[pn];W[rp];B[rq];W[ol];B[ok];W[qk];B[on];W[qc]C[Relatively small. You have to somehow counter Black's wall. Maybe around 'A'.]
LB[go:A];B[fm]C[Second line territory vs. 50 points influence.];W[jj]C[Way too deep! 'A' still has Aji, so when Black cuts you off with something around 'B', things might get ugly.]
LB[ld:A][jh:B];B[ke]C[Too early.];W[lf]C[Cut at 'A' is normal. Extending is strong but you might get seperated at the top and unless you can capture Black's stones, you will lose a lot of points.]
LB[kd:A];B[kf];W[lg]C[You have to cut at 'A'.]LB[kd:A];B[kd];W[if]C[Where is your weak group? 'A' or 'B'? Defend the weak one (around 'C') not the stronger one.]
LB[fc:A][lf:B][kg:C];B[kg];W[kh];B[jh];W[jg]C[If you want to kill something, first read out if this is possible. Then cut.
This is a all-or-nothing-move.
END OF COMMENTS.];B[lh];W[ki];B[me];W[mf];B[md];W[nf];B[nd];W[oe];B[ph];W[mh];B[li];W[mi]
;B[lj];W[mj];B[mk];W[od];B[oc]C[hailthorn [7k]: ty
OceanMon [4k]: thanks for the game
])