I have been using a sprinters starter block with my DD. Seems to give her the feeling of power transfer from the drive leg up through her body. Also gives her a chance to feel that slight lean forward to further enhance drive. Now if I could just get her to take that in to the circle...Hmmmm.
I too have my 99 warm-up her change-up along with her fb before every inning. I want opposing coaches and batters to see that she has a change-up. During one tourney observed opposing coaches huddling and turning their hand over back and forth trying to replicate the motion.