Obviously, the band directors can't catch eveything, or, if they can, can't spare the time to stop a run-through just to mention that one person wasn't doing something right, so in our band, the student leadership is encouraged to fall out of the drill and look for minor issues and fix them somehow, presumably by shouting "pitch!," or "left! left!"

But I have the feeling that there have got to be other ways to get things done. Does anybody do anything different, or just have suggestions for being more effective?

what do you mean? like really minor stuff?
Example?

Are you falling out every time you see something wrong or do you have something like a dedicated run-through where you do this every now and then?
If you do it during every run-through, I would lean towards saying that it's a little excessive.

not every time, but fairly often, maybe every 2-3. minor or one-person things, like posture, facing the wrong direction, or being off-step, and also formations that would have a small group of people being coordinated, are generally left to the responsibility of the students.

another thing we do is shout at people while still marching.

I don't really know why but, I've always had better luck by showing what people are doing wrong and how to fix it than by yelling. That holds true for more than marching band by the way. A few psychology classes have taught me that the mind tends to shut down when it is being chastised...especially in front of peers.

Don't get me wrong though. I do think that pushups (or something like it) are great. What I used to do would be to give the entire line the same "motivation" if somebody screwed up. This did anger many when it was first implemented. However, once people got used to it, they would help each other out so that they didn't have to get physical. It also cut down on my work.

Well, I don't mean disciplinary yelling so much. Just yelling so we can be heard over the music. Usually the laps only happen after something is wrong repeatedly, after someone is told to fix it again and again.

Yeah, same here. I would encourage people to just monitor both themselves and the sets/people around you. I ask people (around me) if they are having trouble because I'm not doing something right, or if there are any problems they see in general. "Am I pulling back too fast?" If there is, "yeah dude, you end up crunching us down.." I do my best to fix it; or just ask people, for example, "try not to get so close to wally in this set because the spacing crunches down, and it looks weird." or, fanother example is that there is a kid (he stays next to me for the entire show) who gets out of step alot during our first drumbreak; so if I see him out of step I start counting, and he recovers. I also remind him that he needs to make his transitions faster so he wont be late and out of step, etc, etc. If its something I have said repeatedly to do, and they dont do it, I say, "Do you remember...what your supposed to do?" and he will say either "Yeah" or "No" and he reminds me he is trying and explains what his problem is. At that point, I leave it up to him.

if your director gives you time in between sets, that is the time when you should mention what you saw that needed improvement. if there is the 'instructors only' talking rule at your school than remember what you saw and mention it to the person(s) at your next gush-'n-go. i think that unless it is a major issue, there is no reason to yell over the music at a fellow band member. if you fall out all of the time, or focus on telling other people when the are wrong, then you won't be focusing on your drill and music.

Okay, mabe I should word it differently. I usually dont talk unless it is a drum break, plus I have the show in my muscle memory. I dont ask him all the questions/give the reminders during marching, but its when we back and forth to our sets and/or at the gush and go.

We do a significant amount of yelling over the music, which I think is the best way to get changes done, because if you tell somebody something between run-throughs, s/he is likely to forget to do it again next time, but if you tell them while they are doing it, they'll do it right, and it only takes doing that a few times for something to become permanent.

We don't have an instructors talk only rule, although we'd probably get a lap if we didn't listen while they were speaking, and in fact, a lot of the responsibility for fixing things in the show is left up to the student leaders, including things like guiding, spacing, good marching technique, and hitting some formations. For the most part, we are expected to become competent on our own marching fairly quickly, then start helping others.

What's a gush-and-go?

A gush-and-go is a quick water "break" You gush water then immediatly get back on the field.

Our director'd kill us if we yelled over the music...or over him for that matter.

He gives a few seconds between every set for section leaders or more experienced members to say anything they noticed and thats when you can tell people something they did wrong.....

I would say not to interrupt a rehearsal at anytime. This time between sets should be practically silent. The only thing going on at this time should be people getting back to their sets, and doing push-ups if they made a mistake in the last run (honor system). What the leaders should be doing is keeping a mental list of specific problems, and then they should tell the people about their mistakes at breaks, and if necessary, teach them the correct way to do it.