What we do is somewhat complexed for someone as simple minded as myself. We get our throwing work in. We then take a 5-8 lbs plyoball and the pitcher lays on the ground belly up. The feeder has his legs His partner rolls the ball down his legs. The feeder is standing up with his feet on each side of the player's arm pits and inside the arms. The player can grab the legs of the feedre. The player lifts his legs up and "hands" the ball to the feeder. He does repetitions of 10 and sets of 3. They switch back and forth. Then the player rolls over on his belly. Now, the player "tosses" the ball up to the feeder by allowing the ball to roll down the calf to the ankle area and then the player uses his hamstrings to curl the ball upward to the pitcher. After this, they do wrist roller and heavy jump rope. One player has to complete 4 wrist rollers and the heavy jumproper has to jump until the wrist roller person completes the 4. Then they switch. Repetitions of 5 wrist roller. Next they do the plyoball work. We have names for all of them like hay bales (the two face away from each other about 6 feet and throw 15 lbs plyoballs in a pattern then switch directions. 3 sets of 12.) Next they do "volleyballs" which are really active squats with the 15 lbs plyoball. Well, we have a bunch that they do. We do these everyday until the season starts. Then, the pitcher's do 1 less set and 2 less reps/set. We also do sprint work up hill. We have a hill and we do sprints up the slope and walk down. You don't have to go until you're ready. However, when you go, you have to drive your legs. They go for 50 feet. We do 12 reps and 2 sets. Then they run "gates." There are two gates at our school which are located on both sides of our school. The ball diamond itself is about 450 feet from the field and that is where the first gate is. The other one is on the other side of the world!
BTW, as I've posted several times, we have a full time trainer. He does series of weights with our pitchers and makes sure that they are on our program. I would post that program but I received it from a university that won't allow me to do so. The rest of our stuff I've gleaned from about 30 books on plyos and weight lifting.
Coach, if I could say one thing, if you can develop a band program that incorporates both stretching and some "weight work" after practice, you'll be ahead of most coaches. You don't have to do all of the stuff we do. If you have any further questions, pm me.