What are you going to show?
That's not always an easy question. What you're in the mood for may not be the most popular choice. If you're happy sitting in your backyard and swatting mosquitoes by yourself, then by all means, go for that Ed Wood Marathon you've always wanted.
First, figure out your audience. My family has two young kids, and since they're a big reason why I started this, they're my primary audience. And for the last six years, we've played a lot of animation.
An eye-bleeding avalanche of animation.
But that's my audience, so that's what I play to. That doesn't mean I can't mix it up a little. Some of my more popular showings have been silent comedies and Marx Brother's movies. So don't be afraid of going off the path a little, just be sure you're audience is going to be okay. And having that solo screening in the backyard once in a while can be fun, too.
I also try to put together a complete program. I collect old cartoons and theatrical ephemera, so it's a great opportunity to show those off.
It also serves the very practical need of putting something up on the screen while I'm taking care of other activities. I put together an hour's worth of pre-show music, which I start about an hour and a half before I want the show to start. I know the sequence of songs, and that helps me make sure I'm on time with my other chores.
After the music, I have about a half hour of what I call "pre-show". These are vintage drive-in ads, generally pushing the lobby or the theater itself, sometimes a public service announcement from a local church. I have a collection of these, most from Internet Archive, but you can also buy dvd's of most of the same material (at generally lesser quality). I've cut this together, so it's a standalone segment.
This starts the final countdown, and I use this time to verify that the projector is working, the sound is correct, and corral the kids.
This is my pre-show reel. I cut a new one of these every year, just to change up the ads and keep it fresh. The one minute kaleidoscope at the beginning is new. I put that in there so I can run over, turn on my projector and focus it. No one much cares if they miss this part.
Normally there's music attached to this part (Raymond Scott's Powerhouse), but since I don't have the rights to it I stripped it out. The rest of this is public domain, and I scrounged most of them from Internet Archive.
After that runs, I throw in a couple of trailers and a couple of cartoons.
I have a real affection for old movie serials, and once or twice I've managed to sneak those in as well. The kids like Flash Gordon (from the '30s).
The biggest problem with this old media, and that includes old cartoons, is find something that isn't sprinkled with racist or sexist content. I've put up some things that are difficult to explain, and with my own kids we talk about whether that was a good or bad depiction, and why. I figure it's a better teaching moment than trying to avoid it altogether.
After the cartoons we have a three minute intermission. The music I normally have here is Professor Elemental's Everyday's a Saturday, which you can listen to on SoundCloud. Now, go out and buy the album, the Professor is a really nice fellow and deserves your patronage.
I usually encourage the kids to get up and dance in front of the screen during this section. Gives them some physical activity before they need to calm down and watch the movie.
I usually dance, too. The neighbors think I'm odd.
After the intermission, this pops up and the show is about to start.
At this point I slot in the movie.
I just found this little clip, and I've started putting it up after the movie. It's cute, and the audience really seems to like it.