The Kickflip must be the most popular skateboarding trick the people want to do and most of them dont even learn ollies before they attempt kickflips, bad idea. The kickflip is a good trick to learn if you learn it good and proper. I will be explaining how I do kickflips, everybody does basically the same thing but a lot of people feel they are doing something different with their kickflips to make them unique. So what Im saying is everyone learns in there own different way.
Put your back foot on the tail in the same position as you would for an ollie. Your front foot should be a small distance away from your front truck bolts. Your foot should be pointing towards the nose at around a 45 degree angle and your heel should be hanging off the board.
Now pop like you would for an ollie, slide your foot up the board but flick your foot of the end of the nose. You need to jump high to let the board flip underneath you. Try to keep your weight central on your board to make sure you land properly.
If the board has flipped properly extend your legs to catch the board and try to land with both feet on the trucks bolts.