Timing & loading are the two essentials.
Jumping high is very dependent on the amount of loading of the kite you can achieve just before you send it. High board speed tends to act against this, as it is difficult to edge hard when the your kite is generating a lot of unwanted extra lift from apparent wind. Faster board speed requires you to start the kite a bit lower to give you more capacity to edge hard. This results in less vertical pop & more horizontal pop, however when you're really powered up, it's easy to turn that horizontal pop into extra height by bringing the kite back forward again (& back) in a "mini loop" while you're in the air.
Good water conditions really help the whole process: flat water, or even better, flat water in between waves & then a smooth wave face.