What I usually do is pick up all the 45 ACP brass I see at the range. As I start to separate it by headstamp later at home, I find that 80% of it is the same brand. So I just throw out all the "odd branded" brass. Seems wasteful, but time & space are money.
There's plenty of 45 ACP brass around, so I can be picky.
I used to sort it by headstamp, but found that I soon had dozens of coffee cans sitting around with those more odd brands of brass that never seemed to be accumulating. It wasn't worth the effort & space.
In 380, that brass is much harder to find, so I save everything and separate it by headstamp. When I run out of matching brass, I shoot mixed brass. I can never seem to recover 100% of the brass I shoot from an auto pistol.
As a reloader, you should consider shooting revolvers more. It feels so good to not pick up brass. No more walking around the range with your head down and everyone looking at you like you have two heads for picking up brass. Not that I minded that much, but it was so great the first time I ejected the cases and put them right back into the box. No hitting the floor, no getting walked on, no funny looks, no explaining. Revolvers have less capacity and more recoil, but more charm.
I still can't give up my autos, but I make sure I keep the calibers to a minimum and try to shoot the popular ones.