Don't you hate it when you drop some plastic thing and it breaks on you? Landfill? No! Sugru! I am a year-round cyclist in Whitehorse, Yukon. When it gets dark, lights are important. The problem is the black clip which attaches the light to the seat post snapped, so any bump in the road would knock the light off.
Step 1: Step 1: ID the Weak Point and Apply Sugru!
I investigated the weak points, namely what motions and in what direction the light would jiggle off, to use the technical term. That is where I applied Sugru as shown in the photo and it's been as good as gold!
Step 2: Step 2: Consider If Sugru Will Solve Your Problem...
Oh, and I also cycle my kids to daycare. (BTW, we have a pretty good paved cycling network along the Yukon River so you don't need to be on the roads in winter). Again, same problem with darkness and this front-facing reflector is important. I think I knocked it with one of my snow boots. Problem, yes, until....
Step 3: Step: Try, Apply, Dry, and 'hi!'...you Are Good to Go!
...you guessed it: Sugru!
I used Sugru both as a 'glue' and structure to hold the reflector in place.
Result? Both have been holding up just fine, and just in time as we are staring down another long winter.