Recently, my sifu taught me a new way of doing forms (new to me but certainly nothing new about it for Wing Chun). It's a super slow way of doing it where you really emphasize the deep diaphram breathing and you tense all the muscles making it kind of an isometric exercise. After about a month of doing it like this, you will never again hear your sifu say "Fix your stance!". When you do it with that kind of concentration along with the breathing, you have no choice but to use good technique and structure. If you don't, there's a good chance you'll fall on your ass. I've found that this has helped every single aspect of my Wing Chun. My structure, balance, timing, speed, chi sao, everything has improved. I encourage everyone who has not yet done this to give it a try. I think you should still practice your forms at regular speed, but this is a fantastic thing to do along with it.