I don’t know if all Meisner acting classes or schools do this, but in my level 2 class we spent a lot of time acting in ‘setups’, which comprise a set of imaginary circumstances within which the actors improvise (and hopefully find their emotional cores).
Anyway, I found that these setups all turned out to work really well as premises for one-act plays. Basically, they start with one person in an apartment performing some activity (ironing a shirt for a date, running lines for an upcoming show, rewriting your will, etc.). Then the second character enters the apartment, usually because the first character invited him or her over to talk about something (invitation isn’t required, at least for a play).
They key is that the characters both need something from each other, and it has to be high-stakes. Most of the setups in class are between two struggling actors or two friends that have some conflict between them (Tom needs Joe to get him an audition but Joe will only do it if Tom let’s him sleep with his girlfriend). It’s easy to make these comedic if you just stretch the circumstances a bit into the realm of absurdity or you give the characters some good comedic traits.
The one thing that isn’t really dealt with in class (because it’s not a writing class) is how to end them, so that ends up being the hardest part. I usually like to kill someone off or start them off as comedies and then reverse it so the ending is dramatic. All you need to write them is a basic premise, what the two characters need, and then maybe some kind of twist. Then you can improvise based on that and after an hour you’ll have most of the work done already–just need to polish the dialogue and tighten up the beats.