Jangling equipment is a nightmare when trying to be stealthy.
My birdspotting scope and tripod need to have a nut tightened on a regular basis (thanks to a DIY repair by the previous owner, my dad). I keep a shortened spanner clipped to the tripod with a small carabiner just for this purpose.
Unfortunately, it jangles terribly when I move the tripod around, annoying me, scaring away birds and irritating other near-by birders.
This is my quick solution to the problem, which could also be used by the sort of chap who keeps his tools dangling from a belt.
Step 1: Equipment
Very simply, all it needs is a 5g sachet of Sugru, and a knife to open it.
Check the instructions on the packet for correct handling and use of Sugru.