If you are not getting height can be for numerous reasons like:
- sending the kite from too high
- sending the kite too slow
- looking at the kite while sending it and so losing your edge
- Going too slow. The faster you go, the higher you jump. If you start edging too hard and too soon, you kill the speed, edge at the very last moment to resist against the kite.
- not having enough resistance with your board and body when kite is over your head
Basically the harder you send the kite without looking at it, and the lower you send it from, and the faster you go before sending it the more height you get, but dont forget to edge really hard and resist with your board rather than "helping" the kite with your legs by doing a small hop, do this at the very last moment when kite is about to reach 12 oclock. Resist in the last moment and edge with your board as if your life depends on it, until the kite wins and rips you from the water.
Hope it helps, i know its a bunch of things to keep in mind but they will all come into place soon. Practice makes perfection

PS Another tip is jump using a wave as a ramp, if you send the kite back right in time with the wave, prepare to go real high, but thats a bit of "cheating" about the right technique (though you still need good technique), but a lot of fun and really a good way to get that much more height
