I've probably posted it before but my tip for those usually is to pretend your board length is reduced to its very central axis length-wise, so basically pretend you're riding some long ass matchstick and so that's where your toes should be resting in a comfortable position. Then the rest is parallel shoulders and having most of your weight distributed over your back leg before you pop, you're not supposed to be leaning over your nose, you're supposed to be mostly standing on your back foot and then when you do pop you're really mostly nudging the nose ahead of you in the direction you're going, as though extending the trick ahead of you. That means the jump feels like a backwards step or leap, in the direction of the tail during which your back foot drags the board along with you and then that's when you extend that leg out, not down for the flick.