Mushers, to the degree we manage to formulate full sentences at all, enjoy bragging about how we need to be not only athletes, but also animal psychologists, veterinarians, carpenters, nutritionists, survival experts, mechanics and tailors.
I am none of these, of course, but by Jove, I've improved in all these areas since dogs entered my life.
I am now repairing assorted harnesses that the dogs, in their excitement at the start of a run, have bitten into pieces. The first time I tried this I stitched the loose parts together, but no thread or twine on earth can stand the kind of pressure applied here, not anything outside of what you might obtain at space agencies, anyway. The trick is to apply a strip of webbing over the part that needs mending, and sew along it's entire length. A lot of repair works like this, distributing stress over as large an area as possible.
Harnesses are the one mushing related thing I never considered making myself. They should be made to spec by people who know what they're doing. A bad harness can destroy a dog, just like a shitty backpack can screw an man for life.
Mushing is one of the last few non-globalized zones, where almost everybody has to make half their gear themselves, and rely on friends and acquaintances for the other half. Naturally, this results in stuff that is either so expensive or has so much emotional value that you end up repairing and repairing before you chuck it out.
Pretty much the way everything should be, actually.