This is probably a bit elementary for some of you, but it’s still something to keep in mind. The “natural” stance most people go into when they catch is to squat down on the balls of the field, with the heels off the ground. While it may be comfortable and easy to get into, it’s also slow and unstable — a point I like to prove by pushing gently on the forehead of a catcher in that stance and watching her fall backwards.
There are a couple of better stances that I like to see catchers use. With no runners on base, the catcher can spread her feet out roughly shoulder width apart, toes pointing out. From there, she lowers her rear end with the weight on the inside of the feet. It’s a fairly comfortable stance that relieves knee stress, yet allows the catcher to get up quickly if there’s a bunt.
With runners on base, the catcher needs to be up and ready to go more. For this stance, she bends forward and begins lowering herself until her back is parallel to the ground, and to her thighs, more or less. Her weight is forward over the balls of her feet. This allows her to be very low while still being able to move easily. If she has to block a ball in the dirt she can move laterally. If she has to throw a runner out she can pivot or pop up quickly.
Putting your catchers into a better stance can quickly help them improve their performance. Give it a try.