As I was building a multicopter, I realized that there was no reasonable solution for mounting my GoPro onto it. So, I used another module and built a plate that can screw into a mounting hole size of your choice. I've used zipties in the past as well.
A lot of the modules originally had GoPro in the name but I changed them to "camera"because I was worried about trademarks. I checked (http://gopro.com/trademarks) and it looks like "You may use our GoPro wordmarks (such as GoPro and Hero, but not our logos) in truthful and factual statements to communicate: (1) that your product is “made for use with” or “compatible with” GoPro’s capture devices or services" so I'm okay.
This whole thing is parametric except (I think for the mount module). That's not my module, but rather YouMagine user fns720's (https://www.youmagine.com/designs/gopro-diver-s-handle#!design-documents) so I'm not going to change it as it works and there's not much of a reason to.
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Do as you please, and if you want to do things outside of the license restrictions, feel free to contact me and I might make an exception.
Enjoy yourself.
Lucas