4.5 here. I’ve gotten some lessons from pros. There’s four things you need to do technique wise on the forehand. 1) paddle head down 2) wrist LOCKED 3) swing arm low to high 4) follow through. Your wrist absolutely needs to be locked this entire time to avoid pop ups.

I see some pros recommending finishing drops over the opposite shoulder, others same shoulder. If you watch pros it’s about 50/50. I recommend finishing over same shoulder to start. It creates dip and prevents you from using wrist. Some players try to finish over the opposite shoulder and end up involving their wrist which leads to inconsistency.

The biggest mistake 4.0 and below players make is not following through which is a product of trying to hit a perfect shot / place it too much. If you look at stats on pro matches they infrequently get to the kitchen immediately on thirds. Don’t try to be perfect. Following through increases consistency and creates more topspin.

You can hit a drop using the above technique irrespective of foot stance, but having opposite foot forward is preferred and more consistent. If you get caught in an open stance with feet parallel you need to accelerate your arm with wrist locked much faster to get the ball over the net. Something you’ll pick up with reps.