Framing practice
Take a couple minutes at the beginning of class to frame the practice. The reason we're coming here is to build a specific set of muscles to move in a very specific way at a very specific time. To get really good at that you have to pay careful attention during practice. If you were competing in rifle shooting, when you shot the target each time you would check and see where you hit, and how far away from the bullseye, and then you would adjust - you wouldn't just shoot like crazy all over the place. You should do the same thing with your techniques. Each time you hit the target take a second or two to see where you missed and where you need to correct in order to get on target. With stances and Forms work, it's the same. Slowing down and correcting makes the corrections automatic and without thought.