I know, this thread has probably popped up a million times,but i donkey kick the ever living fuck outta my kickflips and it makes me wanna die, some have even described my kickflip as a "not late late flip".
Save me friends.
The best way to learn is to stop the way you are currently doing it. Since you can't land it, look at your feet when you do it. Keep in mind that chicken footing leads to you doing a foot plant or a quick land since you are slamming your foot down instead of flicking it and putting it back on the board. That is all a kickflip is. Flicking and putting it back on the board.
Sounds simple but it is complicated because many don't flick it consistently. Repetition can be your best friend or your worst enemy. When doing a kickflip, be calm and don't lash out in frustration because it will only make you lose your focus and then your attempts will get worse until you eventually give up and call it a day. Don't repeat that. Take it from me since it took me 5 years to land this trick.
What really helps in landing is wailing your arms by copying the flick of your foot. When you flick your foot, wail you arm to that direction and hold it until you see the griptape then land. Keep practicing and remember to use your arms as guidance. I realized that everytime I kickflip, I don't land the trick sometimes because I am either foot planting or I am not wailing my arms as a way to guide my foot when flicking. Another helpful way is to look at your board and practice flicking your foot on the board when sitting down. It can really help your form and posture when doing kickflips.