I had a thought the other day: A lot of people have their packs/bags/belts/75 pound tactical vests with 53loaded magazines etc., but what happens when you have a seam unravel or tear something? It might be a good idea to have a small sewing kit.

So what I did was this: I took a military surplus match case (with the screw-on cap), and found I could fit:
A thimble (upside down so it takes next to no room)
several sizes/styles of needles
a couple spare BDU buttons
and black and tan thread

For the thread, I cut about a .5 x 1-1.25" size of thin plastic, cut a indention at each end, and wrapped the thread around it (like a lot of those Christmas light storage thingies)

I can now repair things while out hunting/camping etc., and it takes up almost no space/weight.