I only started doing front squats about 2 months ago, so I'm still getting used to them. But if you're using the clean grip, there are 2 things that really help. 1, release your grip. Like someone else said, you're only keeping the bar in place with 2 fingers. Your shoulders and maintaining your elbows up will carry the weight. 2, don't look down. Whenever I try to take a peak at the bottom of the squat to check my form, I immediately tip forward and ruin my form. Keep your chin and eyes up, especially at the bottom of the movement.