In reply to cam_jan:
What Tom said. Larksfooted a nice little strap from an old compact camera onto a cheap plastic case.
The camera strap has a plastic slider to open and close the loop, so you can tuck it up to your wrist or a crab, or open it up wide. Looks a bit less dirtbag than "just cord" - but you do you of course...
Works with a tiny crab to a top vest pocket for trailrunning, however you want for climbing, salopette strap for ski touring/winter climbing. In all cases, it's handy for photography or nav but totally secure. Just watch your distance from avalanche transceiver if you do that stuff.
Done it about ten years now, works really well. My family don't wince at it (and they would...)
Y