The most important thing when you learn to skateboard is to skate with people that are at a higher skill lv than you, then they can tell you what you are doin wrong. Its so **cing anoing when you skate alle alone, wondering why your board is turning, and you haw to go to the internet to find out that it is something so easy as ceeping your shoulders straight.
To get higher ollies, I would suggesting resting your back foot on the very end of the tail and the front foot in the middle of the deck to allow for more slide. Popping as hard as you can and catching your board in the groove of the nose with you ankle practically resting in the groove will level the board out in the air. after this initial movement slide you feet back to the bolts on the tail and nose to ensure a clean landing.