Ok, so I know microwaves are the devil, but I always burn my popcorn on the stovetop and I refuse to buy a popcorn maker. Conventional microwave popcorn isn't usually vegan, so here's the next best thing.
With my solution, you only need a paper bag and popcorn kernels.
Put 1/3 cup of kernels in the paper bag and fold over 2 times.
Use the popcorn setting or microwave for about 3 minutes. You probably won't need the full 3 minutes, so make sure to listen for the popping to slow and remove sooner.
We like to sprinkle on some garlic salt and melt a little Earth Balance (vegan margarine) on our popcorn.