re: 12 yo Tournament Baseball practice

"Tournament"? I assume u don't mean all-star tourn. too early for that. Assume you mean a regular team that is doing a tournament soon?

Anyways, three times a week would be about right. Divide into stations like said before. In the hitters section have the on-deck batter playing fungo against the fence. Keep everyone busy all the time. At 12 year old you are beginning to be able to tell the future high school players from the rest. try to eliminate bad habits.