alt Hacker NewsPhotogrammetry is one. Generally results in messy geometry though and tolerances get finicky.
The CAD plugin in Blender is my favorite though. Need a caliper to get measurements and then I can build out my hooks/clamps/whatever. FreeCAD for when I just need sketches as I find the solid part workflow utterly confusing, whereas I'm very well versed in Blender.
> Photogrammetry is one. Generally results in messy geometry though and tolerances get finicky.
The trick is a hybrid approach, use photogrammetry to get a draft model into whatever environment you use (like Blender or whatever), then use that for creating the high-quality cutout manually, which will be very easy with a in-place 3D draft model right in the scene.