I EDC a screwdriver with storage for 6 bits in it, but wanted to carry more, so I came up with this little holder that suits my needs perfectly. I took some inspiration from the Wera bit-check and designed an holder with space for 18 bits, arranged in groups of 6. it features a swing open cover, which allows it to be put in a bag or pocket without losing all the bits. You can also push the bit you wish to use out from the bottom of the holder, making it a bit easier to extract.

Printing

I printed mine out of prusament PLA, but any material should do the job if you don't plan to use the holder in particular conditions. 

Layer height doesn't really matter for this one.

I used four perimeters to make it stronger, but it's probably overkill.

No supports are needed.

You might want to use a brim when printing the cover as it doesn't have very much surface contacting the bed

The body should be printed with the holes for the bits facing downward and the cover should be printed laying on its side. 

Assembly

Just flex the cover slightly and slide it on top of the main body, lining up the hinges and you are done.