Holding the small stuff is always nutz.

For the round stuff, I have a set of "V" jaws with the "V" parts on a strip of wood to hold the object depth fixed (the "V" parts are only 1/8" (3.175mm) thick. Also works for rectangles.
You could peruse that 3D printer manual while sitting on the ol' hopper and print something up, but of course that'd only make sense if you were mass producing, like printing up a pile of duckats.