I teach beginner skateboard lessons at my local skatepark, and ollies are always a hot one kids are dying to learn.
I break it down into two parts (most skateboard tricks are like lego blocks - a few basic "blocks" that you learn, then snap together to make tricks
):
1) learn to stand in an ollie stance - back foot with the ball of your foot on the very edge of the tail, front foot behind the front truck so you can see all four of your truck mounting bolts, and maybe an inch or three of grip tape as well.
Now - learn to jump in the air WITHOUT your front wheels coming off the ground. Practice jumping higher, sucking your knees into your chest, and landing back on your board either in the same stance or with your feet landing on the truck bolts.
This jumping (WITHOUT your front wheels lifting!) is hugely essential.
2) step off your board, and put your back foot on the edge of your tail.
The pop is all about quickly flicking down with your ankle - NOT about leg movement.
You absolutely must get your foot off the tail before the tail hits the ground.
So, learning a quick snap is essential. Practice popping your board like this and catching it with your hands when it pops up. If you can get it to pop off the ground and catch it in the air, you have the pop right.
Now, putting the two together is all about timing:
If you find yourself jumping and not landing on your board - practice the jump more, then come back to try again.
If you find yourself not getting your board off the ground, practice the pop more with your back ankle.
There's actually a third part - since this will only leave you ollieing high enough to maybe get over a curb...
Remember the "tuck your knees into your chest" part of the jump?
If you do THAT, and slide your front foot forward, you'll push the nose forward and suck the tail up under you, making your ollie go from "as high as your tail comes off the ground" to "as high as your front wheels come off the ground."
Ah, physics.
