One that could be great time saver - have more than 4 game balls available. Every HS game I've gone to they start the game with 3-4 balls and only add more if the originals are fouled off and not found or they are HR's.
When my son played college ball, they started with 4 balls but had at least a dozen more ready and a bench player would run more out to the ump between innings or as needed.