I have a rotary tool (like a Dremmel) with several bits I can insert into it. I also mount the main body of the tool to a stud in my unfinished wall and I use an extension cable to allow me to hold the handheld portion without the weight of the main body. I wanted a holder I could quickly put the handheld portion into and let the extension cable dangle. I don't have a good picture of the entire setup (will snap one later), but hopefully this makes sense. Holds 4 bits plus the handheld portion.
Best printed on its side with supports. Supports can be tricky to remove from the four bit holders. I was able to use "line" supports that aligned within each tube which were easily removed with some needlenose pliers. Could also remove them with a rotary tool. :-)