I have long been a huge fan of the Mr. Hobby Polisher Pro
sanding tool. This is a simple (and a bit overpriced) battery-operated disc polisher/sander sold to the hobby market for sanding off sprue material and finishing models. It’s basically an electric toothbrush with a sanding disc head. The Polisher Pro comes with 3 sheets of sanding pads in 600, 800, and 1000-grit. There are 45 pads in all. I’ve had my tool for several years now, use it often in game modeling, and still have plenty of pads left. There are also replacement sanding pads available on Amazon (and there are pads available in other grits). This video
introduces a use I hadn’t thought of: sanding layer lines and joins in resin and FDM 3D prints. The video doesn’t have a lot of content beyond that basic idea, but I was happy to discover another use for a tool I already own. I know many will say: Just use a Dremel tool! You can if you have a mini Dremel, but for modeling, this tool is better sized and not as aggressive as a Dremel. And, don’t be like the guy in the video. Always wear a mask when sanding resin and plastic.