Kickflip
(written by ‘misled user’)

Foot Position
Set up in an Ollie position. However, this time, put your foot towards the nose (generally 45 degrees – but you’ll have to experiment to find out what’s right for you).

How To Kickflip
1. As you take off with a nice pop, begin dragging your front foot up the board. In this respect, it’s just like an Ollie, so nothing to challenging here.
2. As your front foot begins to near the nose, flick it downwards and outwards (not forward) to flip the board. Don’t flick with your entire leg, the flick mainly comes from the ankle (this allows the board to flip quicker, and because your leg doesn’t have to come back towards the board, it’s easier to catch).
Make sure both of your feet, especially the back foot, are off of the board. If they aren’t, the board will not flip.
Keep your shoulders in line with the board at all times, especially as you flick your front foot.
3. Once the board has completed about a 180 degree rotation (the graphic/bottom of your deck is facing upwards), prepare to catch your board.
As you see the grip taped side come back around, catch the board with both feet over the trucks. Try and catch the board with your back foot first, because it’s a bit easier.
4. Do not be afraid to land the trick, if you are, you will not land them. This is the main reason why people do not land tricks.

Here's an image sequence of a kickflip: Kickflip
And here's a nice little video: Kickflip Video