This pertains mainly to those all-ages multi-band social hall type shows.
Don't add eleventy-billion bands to every show.
Confirm bands before you tell people who else is on. If you intend on asking a band, there's nothing wrong with saying so.
Don't add extra bands to "help people out" or just because of one of the bands on the show asks. Saying "no" is fine, and shows that you know what the fuck you're doing. Again, there are exceptions to this... but adding 2 bands to a 5 band show is kinda silly, then replacing one of the original bands that drops just takes it to a whole new level.
Solidify all bands & promote with eye-catching flyers all over the place and on the 'net at least a month (preferably more) in advance.
Have a designated "drill sargeant" up motivating the bands as they're setting up. Gently rush them, get mean if you have to. Ask them what you can do to help out. Have a wing-man to run & get shit like extention cords, water for the bands, power strips, and duct tape.
Have someone at the sound board if you need it... have the "drill sargeant" check the mics while the band is setting up.
There's nothing wrong with sharing equipment, especially if you expect all the bands to be there at the start of the show. If bands can't share equipment, do like they do at the Rex. The dude sets up all the bands' equipment in succestion, last being at the back... so all they have to do is peel off the layers & move drums in as the bands go. Precision like this amazed the shit out of me.
Start on time, & keep it running on time. Be foreceful in making up set times, then making bands flow within that time. Be clear in telling bands "you have XX minutes to set up and play, I'll give you a 5 (or 10 or whatever) minute warning". Don't give a set setup time, then a set play time. Chunk it all together. Bands like Gasoline Dion don't (usually) need 15 min. to set up. Give yourself a half hour of "fuck up" time in the schedule just in case it's needed. It's usually needed.
Tell the bands before they start playing what the alloted time is.
In with all of the above... make sure you keep "reminding" drummers to set their shit up while the band before them is playing so all they've got to do is move it out & go. If the band isn't sharing amps, make sure stacks are all plugged together & what-not, and ready to roll out and plug in. Ask bands if they're tuned. Yeah, you'll be a nag, but it's how young bands learn and what old bands expect. If reminding politely doesn't work, nag. Ask if they need help, be so nice it's disgusting, and they'll set shit up so your creepy ass leaves them alone.
In a large social hall wehre all the bands are playing on the floor anyway, you could almost have 2 stages: One setting up & tearing down while one's playing. This would provide non-stop rock. They could be side-by-side or in pposite corners of the room.
If it's an all-ages show in some kind of social hall (VFW, VFD, "nationality here" Club, etc.), sell pop at least. A case of FAYGO is dirt-ass cheap, and you'll make a profit selling it at 25 a can. You can do the same thing w/ snacks & someone with a Sam's Club membership.
Hook a CD player up to the PA and play some weird-ass shit in between bands. Quiet time is bad. Funny songs are good.
Don't bullshit the bands. No one likes to be mislead, lied to, or pass on false information to friends, fans, or other bands.
Out of town bands should not ever play last in day-long all-ages social hall shows. This is a ridiculous idea to make them go on last... unless you're positive that they're the largest draw to the show.
If a local band is on a day-long social hall-type show don't put them in the middle, and give them a longer set time that everyone else. Especially if only 2 people are standing up front to watch them and everyone else is staring at the floor waiting for the next band.
For bar shows, be nice, let the out-of-towners pick the sput that they feel most comfortable with.
If your hall rental time is up at 11:00pm, plan on the show ending at 10:00 or 10:30... because you will run late, and will need the alloted fuck-up time. Didn't we cover this earlier?
If your target crowd is under 18... remember Jr. driver's licenses in PA now have kids needing to be home at 11:00pm. So, the show should end by 10:00pm if you want everyone to watch the last band before they have to haul ass to drop off Jimmy, Suzie, Betty, & Bobby to avoid the wrath of the bored small-town cop who gets to pin them for driving on a Jr. license at 11:02pm or mom n' dad who may not be cool and might want to revoke driving privliges.
Set up the order before the show, and stick to it. Email it (or call it) out to the bands at least a week in advance. If anyone has any complaints, fix them one time, and then only. The day of the show... do not fuck the order up in any way. If a band whines about their time slot, TFB... they were told about it a week in advance. "Special Requests" had to be in by then. They either play in their alloted time slot, or not at all. Switching shit around the day of the show is incredibly unprofessional... on the promoter/booker's part, and on the band's part. Promoters, don't be pushovers, and bands... don't go all rockstar.
This is all that comes to mind now. I'm sure more will come. Feel free to add, comment, refute, or agree. Also, pass this on to other promoters/bands so we can get all the input possible here.