Based on what I saw, your knees should be bent more as they look pretty straight more than they should be. Ever done squats in the gym? Back straight, knees not passing your toes, etc... same deal on a board. Hips forward on toe side, like a 8th grader trying to grind with a girl that won't get close enough. Hips back on heel side, just opposite of the toe side stance. People think you need to sit more and crouch on heel side, but that will hurt you more in the end and give you less edge hold.
Think of a box around your board coming up at you, and you don't want to go outside the box more than a little bit. Get those knees bent, and focus on tilting that board up on edge to make a turn rather then rotating the tail around by kicking your back leg (which I saw a few times) and flailing your arms around (which I saw more often.)