Different techniques for different tricks. I just recently started doing raley's off the kicker at OWC. I found that I get my best ones if I time it perfect so that I cut across and leave the ramp at the top, but sometimes my timing is off a bit and if I keep my edge I'll go off the side a bit and lose a little air time. So I tried to ease up a bit if my timing was off to go off the top of the kicker, and that was definately a mistake. Lost all the tension I had built up.
Just going over the kicker in general though...I would say don't be comign straight at it..start out a little and edge in. Keep your knees bent and stand up when you reach the top of the kicker. I had some scary moments with throwing tantrums off the kicker...I would be thinking about what I needed to do for the trick so much that I would try to leave the ramp to soon and I almost wacked my head a few times.
The biggest no-no is to hit the ramp while still on an edge. You have to hit the kicker with the base of the board or its just gonna fly right out from underneath you.
It could be a mental thing to. I had the hardest time hitting the little a-frame rail because I kept psyc-ing myself out and when I hit it I would be all offbalance.
I still have a lot to learn riding, but those are some of my thoughts