Magpul Bev-block, geisselle reaction block, magpul armorers wrench, punches, nylon and rubber hammer, roll pin punches, #2 pencil, dremel yep.
Edit. I forgot to add; silence. I have to work alone. If I'm talking I get hella distracted and then I do stupid **** (not damaging stuff) or forget stuff. I like to take my time and lay everything out and fit up stuff and lube stuff and plan my approach and then start.
So it's like the guys who say when you reload, dont have any distractions, yep like that
Probably my magwell and upper reciever vise blocks
I like assembling ARs. Roll pin punch set along with the plastic hammer and armorers wrench go hand n hand though
Most useful; I have a heavy work bench on wheels (like a small medical equipment cart). I can attach my heavy garage bench vice & magnified shop light. I also bought plastic jaws for the vice. Absolutely fantastic for hammering on parts & pins.