I couldn't find any satisfying pencil clips, so I made a couple.

I used support obviously. I printed them with the shank flat to get the most strength from the filament as well as the best finish for the show side.
The elephant prints easily and diamond uses a flat backed crystal glued in place for decoration. On the paint can clip, I added a small post as I was not able to get a good print without it. It breaks off easily and came off with the rest of the support structure for me.
I had to use a brim, 15 lines and 2 layers to help everything stay together while printing. I haven't tried printing on end, but it would work well, sacrificing a little strength and alignment of layers for printing without support.
Enjoy!
Simonarri on Instagram