The most impressive high-resolution 3D scans I've seen so far are those that use photogrammetry. The rules to achieving decent results isn't rocket science:

A digital SLR would be preferable since it permits some of the crucial focal length and aperture adjustments. Aperture should be set to minimize depth of field (no bokeh). Use or rent a quality lens that won't introduce chromatic aberration at the edges.

Shiny and transparent surfaces ruin the process. Make the region matte by dusting it with baby powder or spray with a washable paint. Shoot either in a light tent condition or outdoors in a total overcast (sunless) sky. Photogrammetry will be helped by picking up the focused, unevenly dusted texture on the surface.

Double-stick a coin or other reference object in an unimportant adjacent area. This can be used in the resulting mesh to ensure things are scaled accurately.

Agisoft Photoscan would be my first pick since it doesn't rely on a cloud subscription model. It's been around long enough to generate a bunch of YouTube and community support.



By comparison, I've tested 123D Catch years ago only to find the resulting low-res mesh to be garbage for reverse engineering. Noobs initially gush over the results, but once you strip away the color/texture/UV data, the underlying mesh is generally unuseable. A quick look through the 123D Catch gallery illustrates the lack of high-res scanning being achieved.