I'm not good in deep reviewing, however in this game I see certain move categories, which easily would promote you >= 3 Stones in rank, if you avoid them
a) Caring about single stones
- On move 40 you capture a ko, while your surrounding stones are not really in danger. Try to see the difference if you played at the position of White-41 instead
- Same thing for move 52. Here, the W stones are more or less dead anyway. You could encircle them on a larger scale (e. g. by playing around tengen) or do something different e. g. C2
- Move 60 saves a single stone and maybe worth 2 points. Try to find out, if there are any bigger and/or more urgent points on the board.
b) Letting the opponent enter your moyo / almost secured territory
- On move 85 W finds time to play C2. This may look small but the difference, if you've played there before (remember move 60?
) easily approaches 10 points. After move 85 you still didn't block but let white further in during moves 111-113. Except for the points lost there, the group looks somewhat weak after move 113 (and got finally killed, later in the game).- The same thing happened in move 120-122; move 120 costs you about 12 points with no need (taken aside the fact, that GnuGO blundered later on by not protecting the cut at S15...
)Thus, every time you are trying to capture or save one or two single stones (unless they are of special importance, e. g. cutting stones) ask yourself if there is nothing else more urgent (I'm now able to letting go off up to four stones easily, with more than five stones I still have problems
). Further, in some cases it is really important to block or protect your existing structures from being entered, even if this looks slow. Think of the proverb "Urgent moves before big moves"...
stone, which makes 
a bad wedge.
at R18 works, then everybody would play it, instead of the joseki keima at Q18.
:
but 
refutes it: