I rip them off and throw them out unless I need twine. I sewed more garments than quilts and selvedge got in the way.
When I rip, I've found a bit of fabric that isn't straight on the grain. Gives me a straight edge to work with.
I don't have any brand loyalty. I look for the colors and prints I want. I use the old Pantone system. (It looks like paint chips)