Alright, let's bring the flip to the wall.
Now that you know how to do a flip from a glide, you can easily do a similar feat by the wall.
Step back about 2-3 meters from the wall.
Push off the bottom into a glide, however, this time you will have one arm by your side and one arm in front of you (this will simulate a freestyle stroke).
When you are close enough to the wall (this varies based on the height of the person and the ability to tuck into a ball) perform the same drill as mentioned in the previous post.
To recap this, when you are gliding with one arm up and one down, start your stroke with the arm that is in front of your head, when this arm is moving toward your side, tuck your chin to your chest and use your stomach muscles to smoothly roll into a ball.
Once your head is nicely underwater (basically you are head down now), start rolling your knees to your chest and finish the smooth turn.
Now listen carefully here.
When you feel your feet hit the wall, just give it a strong push.
You should end up pushing off the wall on your back.
Do not twist your body, just do a straight over flip.
Do not worry about your arms. Just keep them at your side during the push-off.
In other words, you push off with the head first with arms by your side.
When you are comfortable with pushing off with the arms down, it is time to move the arms in the correct position.
The arm movement starts at about the time when your legs are beginning to move from straight position (at the surface) into being tucked to your chest.
Both of your arms should be at your side at that time, so we just need to get them into a perfect streamline.
This is actually simpler than it sounds.
You see, when your body flips around, your arms actually stay in one place.
They start by your hips and when your hips flip over, they still are in the same position, but this time your body has moved, so they are above your head.
Slowly move them behind your ears and stretch.
Now, when your feet hit the wall, you can push off and you will glide off the wall on your back and come up to the surface.
Practice this many times, before you move on.
The only thing left now is the twist to your front, so you can start swimming freestyle.
Immediately after the push off the wall (still underwater), you should start twisting on your stomach, so you come up in the same freestyle position as you started out in.
To help you, you can imagine pushing off the wall in a corkscrew fashion.
Use your feet to start your twist, however, don't be too eager to twist; it is a nice smooth slow motion (there is plenty of time to do it before you surface and start swimming).
Once you have handled the wall flip, feel free to get into more advanced exercises that will help you improve your flipturns.