I'm taking lessons from Jeff, and last week we discussed some handicap games from my local club where I played white. I thought I'd briefly share some of his general comments about handicap go, because I found them quite interesting.
First of all, he says, in Asia it is generally considered harmful for your own go to play white in handicap games. This doesn't mean you shouldn't do it of course, since you have a responsibility to help other people grow.
Any handicap game is always a teaching game --- white should play to win, but that is not the primary task. The task is to set a series of tests to black: every move should be a test, to see if black knows how to handle the situation. If black does, fine, the student passed the test! If black passes enough tests, they will win, good, move on to lower handicaps.
Familiar handicap go ideas follow: white should not chose simple variations because if it is too easy for black to see how to respond, then it is not a good test of their abilities.
White should never defend (unless it is absolutely necessary, or white is already ahead). A weakness that would immediately warrant reinforcement in an even game should be left exposed, and is to be seen as yet another test for black --- how will you take advantage of my thinness?
I'll end with a few examples from the game I played with daal yesterday (see this post). In this situation,
was a test and black responded correctly at 
(instead of blocking which might lead to trouble if white cuts), and 
was another test to see if black knew how to resist this kind of kosumi, which can be seen as the most aggressive way to respond to an invasion in many cases.Later,
was the test that black finally failed (black should simply hane on the other side to keep white separated). Before this I did not feel that I had a chance in the game, and I thought black would win.
And there is nothing wrong with testing your opponent in an even game, as well. 