Hi myusernam,
The technique of boosting big is different for different types of kites. The one thing that remains constant across all types is timing and edge and release. If your timing sux, so does your airtime! If your edging and release sux, you'll swing under your kite and likely luff your kite.
How hard you send your kite and what you do with it once you start ascending depends on the kite. General rule of thumb is send your kite from between 10.30 & 11.00 back to around between 12.30 & 1.00pm. Generally the kite needs to be sheeted in (Pulled in on the bar to increase power and turning response) from before you send it (pulling in on your back hand to redirect the kite in the opposite direction to that which you are travelling), until after you have landed.
Would anyone be interested in an afternoon boosting clinic? That could be fun.

I'd be happy to bring along a few awesome boosting kites if anyone is willing to challenge their own altitude PB. [}:)]
How about it?
Good winds,

PS. Better?