Step one--don't overstep what YOU think is funny. Quite often the kids have a great grasp on the local sense of humor. For instance, I do not find men in womens clothing the least bit funny, but the locals here love it. Let the kids come up with their own bits, starting with simple moral message plays such as "look before you leap" or "jealousy often leads to loss", and let the students develop the skits from there. Sure you will have to keep some of it off the stage, as most teenagers think of two things first--sex and violence--but once you have removed those things, they can be pretty funny. Encourage all of them to write, form a cast, and to put it on for the class. Even if it stinks, it is a start, and sometimes their fellow students can come up with a way to improve or save the show.
Step two--If you are going to use prewritten shows, make sure they are short and easy to do. The audience comes out for only one thing, to see someone they know on stage. They don't care if this show is the most award winning one act in history, if their BFF isn't in it, they aint comin. Make sure the kids tell the family and friends that they produced or directed or choreographed or teched or had a major part in the production of this show. Then everyone who knows them will want to see it. Steal what you can, and make it your own. Rocky and Bullwinkle did a great job on some classic fairytales, maybe you could too!
Step three--Promote the living crap out of it! Go to the old school methods of promotion--hand bills, Sandwich boards, Ballyhooing, flyers, posters, school announcements, have the kids put on costumes and stand outside of Wal Mart with hand bills, send home several letters to the caregivers of your amazing students. After two years with a tent show theater I realized the power of having a hand bill handed to a potential patron by a pretty girl in costume. It is simply a more complex form of word of mouth. If no one knows, then no one goes. Putting butts in the seats, that is the main objective.
Step four--Price it so folks think your reasonable. No one wants to pay $10 to see a high school show, so if you do 4 evening of one acts per year, at $3 per seat, you can keep you price for your musical at $5. This year we made over $3,000 in admissions for the evening of one act shows. No cost for royalties because we write our own. Is it as Saturday night live or Mad TV...sometimes better! And some of them are just plain bad. But, it is worth the effort on my part because they do all the work in class! Dress rehearsal takes place the afternoon of the show itself. We make a party of it, and have everyone bring something to eat (kids always eat). Keep the price low, an some of your patrons will want to come twice!
Step five--Get adult supervision! I average 75 kids backstage at any of these shows, and they do misbehave! I try to have at least 3 adults patrolling backstage to enforce my one major rule...."DON'T TOUCH EACH OTHER" You would be amazed at how that one rule can control the drives of the average teenager. With parental help, or fellow teachers, things go much more smoothly during the average show. try your fellow teachers, many of them have stage experience and know what it is like backstage. Offer them a free pass to the musical if they help during an E.o.1.a. I do have some favorites in my teacher buddies, but many of them come back again and again, because it is fun.
Step six--Do not forget the motto DARE TO SUCK/STINK It might look really bad to you, but to their parents, it could be a miracle! This may be the first time their shy little girl ever spoke that loud, or they could actually see leadership potential in a boy too small to play football. We are in this as a craft, and all crafts can be learned to many different levels of perfection. DTS stands for the starting level of anything you have ever wanted to try but were afraid to fail. Go ahead, help a kid fail when it doesn't hurt, and that kid will try again and again until one day you realize they are actually good.