This is my first thing upload!
I got this great little driver set from Bunnings and thought I needed a way to keep all the parts together. Here's my result.
Print it and stick the bit holders on with double sided tape or glue to your preference :). The empty holder pictures show the double sided tape in place.
With my printer, a 20% fill and 2 layer wall didn't quite fill all the gaps. The empty holder is print #2 and used 30% fill for a much nicer result.
The rubber handle and driver extension are tight fits and so wedge in nicely to prevent them falling out.