Looking up the mountain is not a bad idea IMO. This is how I teach our beginners how to turn. When you're on toe side slipping down, you shift pressure onto your lead foot (similar to how you initiate the pendulum). As the board straightens out, you turn your hips to face uphill and allow the board to turn under you. It's like imagining your eyes are on your hips and you're looking up the hill with them. This eliminates the counter-rotation that people use so often for their toe-side turns. Once they get the idea that their body initiates and their legs follow, you obviously tell them to stop looking up the hill with their head but I emphasize keeping their entire body (knees, hips, shoulders) inline with the board.
Everyone will catch an edge when they first learn this and it's almost 100% caused by leaning back. It's 100% natural.. your board is picking up speed and you might not be comfortable with it and so you shift back and try to stop. You have to trust yourself and the board and lean into the fall-line so you stay centered.
Here is a good vid:
YouTube - QuickRide System Steps
Skip to 6:00 if you just want to look at the turning section. When they tap on their knees, they're saying where the pressure is. So if they tap on both knees it means equal pressure, if they tap on one knee it means that's the one with the most pressure. But notice how their upper body is the first to turn and they allow their lower body to follow.
Hope that helps