There are several pitching drills but most important is repetition. make sure to spend time practicing hitting the corners of the strike zone. Make sure to remember the feel on how to hit the corners until it becomes a natural movement

http://www.softballperformance.com/softball-pitching-drills-how-to-improve-your-accuracy/

You can put up a sign that is about the size of the girls you pitch to then take like two long socks and make them a ball and pitch to that about everyday until you start to get better.
That's what I did and it worked for the most part.
Hope everything works out. (:
-Georgie Ray-

you could do an inside, outside, then change-up drill at pitching practices. it works for me so it MIGHT work for you

Repetition Repetition Repetition! I also work with my students using a heavy ball, light ball, regular ball....this helps on release point because with each ball your arm speed will make the release point a bit different bc of the weight in the ball. You will want to do reps with the weigthed ball, then light ball then a regular ball. I also would recommend that you do repetition drills- you stand on your powerline and your catcher has a ball and you have a ball. When you throw the ball the catcher throws the other ball to you so you are working with two balls. You will throw as quick as you can for 1minute straight trying to get around 40 pitches in the minute. This gives you good rep without using your full body, as well as mental toughness and works on armspeed.
And the kids favorite is the tdrill- I make some t's out of pipes and some other materials but all you do is put a ball a t on homeplate and try and knock the ball off of the tee. You can start with using a big ball like a basketball or volleyball and work your way down into a small ball. You can do this drill standing on your powerline or in full motion.
Hope all that helps! Good luck with your pitching =)
Coach Mary

I'm guessing you're nailing your spots now, but thought I'd throw in some ideas if you aren't already doing them.

-Always strive to improve form. Never hurts to check in with a reputable pitching coach and see if your form is dialed. Keep in mind that each coach is different and may try to change something you know is not necessary. Use this checklist as gauge for yourself: www.softballclinics.com/handout2.pdf (Pages 16/17)
-Distance pitching. Start at 3/4 distance and throw 3 pitches. If you hit your spot 2/3 times, you get to take a step back. Keep going until you can't hit 2 out of 3 times. You have to take a step forward if you miss 2+ times. Compete with teammates to see who can go the farthest
-Put softballs on a series of tees, or on the ground lined up behind the plate and try to hit them. Compete with teammates.
-Pitching competition. With a teammate, take turns playing innings. You go up first and pitch to pretend batters. Keep score by counting strike outs, walks, etc. You might even count hits if you leave a fat one across the middle of the plate. Catcher or coach is the judge. Switch after three outs
-War: 2-3 three pitchers throw 10 pitches each. The others get to stand outside of the circle and do/say/scream anything they want to try to distract you. Losers run bases, push ups, clean your cleats, etc...

Keep it fun, but serious. Remember that 100% practice makes for 100% game time. Never practice half hearted. Even in War, you will laugh and get silly, but this game really challenges your focus.

Just realized Mary had already suggested the t-drill game--one of our favorites with all the players.