With both your feet on the board, lift up the heel of your back foot so your weight is on the ball of your foot and your toes. That part of your foot should be centered at the tip of the tail. Your front foot should be about 2/3 of the way up the board, angled slightly forward. Your toes should be near the toe edge of the board and, depending on shoe size, your heel may be hanging off of the heel edge. Smack the tail to the ground with your back foot and jump off of that back foot--getting the timing down is probably the hardest part. As you jump, your front foot slides up to your nose, pulling the board into the air. At the peak of your ollie, level out your board, then wait for the landing. Always land with your knees bent. When ollieing a gap, try not to think about clearing it; instead, think about popping a nice big ollie. The hardest part about ollieing most gaps is getting in the committed mindset. When you're in the air, spot your landing and keep those shoes on that grip tape until you roll away.