I have a suggestion if I may - there are a lot of ideas here that obviously work and work well - however no one has mentioned safety. You might consider A, if sanding, wet sand, B. wearing a protective mask of one sort or another, C. performing the work in an operating airbrush booth or D. a combination of A , B and C. The byproducts of cutting and sanding resins isn't exactly good on your lungs in the long run (This from someone who has a screaming in both ears earned from standing too close to large bore aircraft engines running at 52" of Manifold pressure, looking for leaks and loose objects and not wearing ear protection!)