I warm up 135x10, 225x10 and then do sets of 5 progressively until failure (starting at 315 and adding 10s). My grip in my left hand fails at about my 3rd set of 365, but with straps I can manage 405x5 np (just got straps and worked my way up to that, probably can do quite a bit more). If grip is failing I would recommend straps, but either way sets of 5 working your way up to failure should help. I would also switch up styles and do traditional, sumo, and Romanian. The trap bar is also easier and should still help build strength