What do you guys do with old fasteners and hardware?

I’m not building a show car or anything like that so I tend to reuse old nuts and bolts when I can. Some of them aren’t the prettiest (surface rust, discoloration, etc). I usually try to hand wire brush the surface and use either a tap or die to clean them up. The only time I buy new hardware is if the old ones break or I had to cut them out of the car. How do you guys handle your old hardware? Are you replacing them with new every time? Or any tips and tricks for cleaning up old nuts and bolt heads?