Re: What do you use for a work bench?
Well, if it's just a pick up change and nothing else (routing, glueing, sanding)
then I've got either an old wooden desk with drawers covered with carpet
( swing lamp, power strips, shop vac beneath, soldering station to side, and other goodies) that butts up against a wall with some component organizers, and wire rack ... pretty easy to make your own, a sturdy wooden desk, with good leg room, a drawer or two for tools, components, and other supplies ... ample work sapce, and space to the side for other things can be found at yard sales, flea markets, second hand furniture stores, etc. So once you get that you can customize it anyway you want. I say a wooden desk/work bench thing because you can screw/mount all the extra stuff you need right to it (power strips along side and back, that magnified swing lamp, a small vice or parts holder, or what have you).Plus most desks are at a pretty comfortable level to work from, a good comfy computer chair and you are there.
For what you asked though, an old blanket on the floor or towel (protect the carpet from falling solder), and protects the instrument from getting scratches from a plain or hard wood floor, those fret rest things are helpful, and fairly cheap also. Don't have any pets or children running amuck, and be careful where you put your soldering iron, you may have to elevate the body a bit and cushion the headstock. Folded towels do nicely, although nothing to fluffy (causes problems with lint in polishing, cleaning, etc.)