Cutting in to a wave
Cutting into the wave is quite important for the jumping part. Because it gives you the most speed coming into a wave so that you can get the most air possible from a wake.
What you do is start to turn into the wave and then start to lean more and more back also turn you board more and more towards the wake placing the bottom of your board to face the boat. You should turn into the wave slowly because if you do it too quickly you will realize that the boat doesn't catch up with your sudden turn and you slow down till the boat catches up again and you get ripped towards the wave. This gives you less speed and could cause you to fall.
Popping off the wave
popping is how you will get your air of the wake. When you cut into the wave you will lean backwards and bring your toes up. If you run into a wave like this you will probably just cut right through it. so when you are almost on top of the wave bring your toes down again quickly flattening your board over the wake so that you launch upwards with a flat board, but you still had your speed from the cutting into the wave.
When you bring you board down you should pop straight up so that on the moment you pop off the wake your body is moving upwards and your down force is very small giving you more air.
How to have your body while in the air
if you popped up your body in the last step this is easy. Just keep your body straight with your hands holding the line down so that you don't have to panic with your hands out forwards. This will basically just lock your arms.
Your legs need to be straight, having it completely straight will be quite difficult but about as much as the guy in the picture you can even bend your legs a bit more. But this is just to make your landing easier if your legs are straight and not completely bent.
Landing
Landing is fairly simple as long as you followed my earlier tips. In the air you should have had your legs straight, or at least not completely bent. So that when you land you bend your legs on impact using your knees as suspension so that it doesn't hurt and make you go wild, if you aren't able to bend your legs for suspension the landing will most probably be very difficult. Especially when you start to get good height on your jumps.