Berg sidecutters

For small clippers used for soft wire, I use a small diamond hone to clean up divots from bozos using them on hard wire and to get the jaws so they meet properly. You can usually do this once or twice with those small ones, then you run into problems with handle stops. If you're talking about proper electrician's side cutters, my dad used to grind those to save money, I've got a set I inherited where the ends of the handles meet. Will still chew off #12 wire, not my first choice of tool for it, though.

Stan