General power tips for FH outside of the wrist being stopped to point at the target with legs, hips and shoulders doing most of the follow through are running fast and not crossing the legs into an x step. Leaving the right leg right of the left leg is fine and helps keep you balanced, when you turn your left side to the target. Aiming with the running direction to the target being aligned with the line between the shoulders at the reach back. Also keeping the eyes on the target at all times. So you need to pivot the body under a fairly non moving head and that needs warmed up neck muscles for safety reasons.
Flat shots need running on the center line of the tee and planting each step on the center line. Anhyzer needs running from rear right to front left with the plant step hitting the ground to the left of the line you're running on. Hyzer is the mirror of that.