Feel free to share tools you find handy. They don’t have to be unusual, although that’s more fun!
Rigid’s Copper Pipe & Tubing Cutter.
Apparently it’s adjustable to cut pipes with a diameter between 1/2 in. and 3/4 in. copper pipe tubing…and it automatically tightens which is handy.
Seton’s Blank Setmark® Snap-Around Pipe Markers
These are snap around pipe markers made of vinyl, not paper, and they are not stickers. This can be a decent option if you’re almost sure customers (homeowners) will get confused changing their house water filters and want something obvious, that won’t degrade over time.
Post-it Extreme Notes
These could be useful in dusty environments - thinking cabinetry and casing cutting/installing, sheetrock cutting/breaking, etc. Apparently they are extra sticky and can be used outdoors. I mean working indoors is plenty fine, but maybe you will be able to put this to the test.