I've really got a lot of room in mine but have set some up in small garages before using rolling work benches and small saw tables. I basically used 2x4's and framed the bases and mounted 3" caster wheels like the ones on shopping carts on the bottom. the trick to succsess is don't make the tables or work benches taller than they are wide if you mount them on wheels. I mounted my spindle sander, power miter saw, edge sander, and thickness sander, all on rolling stands. I made the heighth of each so they match my stationary work benches, and table saw off fall table height. Works great! i set up my portable table saw on the end of a long 2' wide work bench in the center of the room. i set up a sheet a plywood that folds down out of the way on the side of the bench when i'n not using it.
That's another great space saving technique. espeacilly for long skinny shops or single car garages. mount your work bench on door hinges screwed to the wall. fold it up into position and put a couple 2x4's under it for legs. i use one off these for a glue up table to do my epoxy lay ups, and assembly work. the cool thing about a folding work bench is that it never turns into a catch all! you are forced to clean up your area.