it can be tough to instill a will to go all out, especially when you're losing. It sounds like you have a quick athletic team, if that's true I'd throw a full court press in 90% of the game, where the first pass gets doubled and a help guy comes to the middle to get the second pass - if you have a 10 second violation, you'll draw that, you'll draw long passes, you'll generally get steals. Now of course to put the press in you need to score. At the U12 level, its good to have a motion play or two and you definitely need some sort of zone offense, but keep it simple. Encourage kids to go to the hoop, as they'll get to the FT line, run simple screen and rolls, that type of thing. With my freshmen, unless I have a physically developed kid, I don't let them shoot 3's (a 3 shot is a line drill in the next practice) - everyone wants to shoot 3's, but until your body is mature, you're just creating bad habits for later.... instill the teamwork/intensity in practice and it'll translate to games - do loose ball drills (be careful though!) - do rebounding drills, make the kids have team spirit or make them run (I know in the 2000s running kids isn't as popular, but its still effective) - one of my favorite team building drills is water for FT's - where you give a kid the ball and say if you hit 2 in a row (or 1 in a row if they're particularly weak) the team gets their water break - if/when he misses they do a down and back and you throw the ball somewhere and have them fight for it - this creates hussle - same drill until someone reaches the goal... practice is the #1 key to an effective season - if you can practice/scrimmage another team even better b/c I find practicing against yourself can create problems with overconfidence especially if the second unit is weak - but correct all mistakes as quickly as possible - practice doesn't make perfect - it makes permanent - good luck!