Step One To begin you should be really comfortable at just riding around, as you will need good balance to complete this trick, make sure you can easily roll over cracks and down curbs.
The positioning of your feet is an extremely important step. The ball of your back foot should be on the rear of your skateboard in the little pocket towards the corner of the tail.
Your front foot should be 3cm below the bolts & the the arch of your front foot should just be over the edge. The ball of your front foot should be just in front of the very centre of your deck.
The ball of your back foot should be on the rear of your skateboard in the little pocket towards the corner of the tail.
Roll the back wheels of your skateboard into a crack on pavement. Make sure there's nothing around you to fall into.
practise practise popping your tail and sliding your foot up your skateboard. As shown in the photo. Reapeat this step until you can do it comfortably. This may cause damage to your shoes.
Now it's time to put all the steps together. Pop the tail down on your skateboard slide your foot up evening on the deck evening it out in the air, then apply pressure for a clean landing.
Keep practising and you will get higher and higher! The Ollie is an important part of skateboarding and is a very useful trick to learn