i have a few different methods to break them in (I use all the methods)
-first I blow a hole in the cutter portion by cutting a live 120 ckt (not 277 !)
-then I drop them a few times off the very highest point at any job, and never over anything soft (like your helper or some dirt), they must hit concrete, steel, (or in a pinch, wet concrete)
-before the next step, its usually a requirement that they are run over by something heavy, like a track loader or a D8
-this step is important, you must lose them for one to three weeks by placing them in some ungodly spot that you would never believe they you could have left them (inside a ct cabinet or live gear, perched inside an acoustic ceiling directly above an extremely expensive and fragile piece of equipment, or left in the dish of a brand new gov super secret satellite dish on a job where the guard dogs get holidays and weekends off but you don't)
-finally, accidently drop them in a bucket of crap that some roofer left sitting by your trailer
-once you clean them off, if they still work, they will be damn fine pliars !
-if you haven't already put your name on them, DO NOT put it on at this point, or you will have to go back to step (lose them again for 3 weeks)