When you start your SLOW turn outside the wake you should get your body in position as you will go off the wake except your knees will be bent just a bit more.
Don't lean too far back because you will go screaming in and will have to let off before you hit the wake to be in a good body position. Just start your cut easy pick your line to the wake keeping your eyes on the top of the wake and stay on that line keeping your body in one position during the entire cut. You do not need to pull back against the boat like a tug of war, that's a mistake because it's too easy to get your body out of position. Lean a little away and keep your line, and keep your body in one position all the way into the wake. Look at this video of Shaun Murray and see how once he initiates his turn he stays in one position all the way through his cut. http://www.dpcfilms.com/wake/videos/ShaunMurray-BlindJudge.wmv
As the boat moves forward and you stay on your line to the wake, you will build tension (energy) in the rope. Stay steady. Don't lean back too much and don't let off when you get to the rampy part of the wake. Shaun is leaning back hard in the video because he's doing a raley type trick and he obviously knows the progressive edge well. When you get better you can lean back more but it's not necessary yet. Leaning back too hard when you're first learning will just cause you to let the energy out of the rope at the wake instead of riding up and through the wake bacause you'll be going to fast.
When the front of your board enters the curl, STAND TALL, keep the handle low (near your hips), keep your eyes on the landing area and your body straight. Don't stand too early because it will let the energy out of the rope.
You will fly.
Don't pull the rope, it pulls you forward, off edge and releases your energy (tension) in the rope as well as potentially pulling you off axis and off balance. Let the boat do the pulling. You simply stay in one position on you line to the wake and allow the tension to build automatically as the boat moves forward faster than you do.
Ask someone in the boat to watch the rope as you leave the wake. If the rope is tight, you're in good position because it means there's tension on the line. If the rope is slack, that's bad and you've allowed yourself to come off edge loosing all of that precious energy.