How do you guys round off the edges of your EPP foam? I'm trying different methods but I'm just making a mess.

Belt sander or drywall sanding screen (looks like window screen - try first with a fine grit)
Seems that it likes to be "sanded" in one direction only, if sanded in the other direction it wants to grab and rip the foam. Use light strokes at first.

For large radius rounding I use a small hot-wire bow. Then sand it as described above.

Thanks, I'll try them.

I use a bench-belt sander most of the time. A one direction sander also works.
If your on a budget, a drum type sandpaper roll does ok, but use finer snading grits so you don't dig in too much.

First shave down the edges using 45 degree slices with a new sharp blade and then drag among 80 grit sand paper in one direction only, then remove the fuzzies with a trim iron or the side of a hot glue gun tip.

The tips, stab and fuse pod were all square, then rounded using this method.