Shoutout to the old timer in Wichita who showed me the paper trick for indicating a vise
He tore a strip off his setup sheet, stuck it between the jaw and the part, and said "when it drags, you're within half a thou." I've used that on every job since, so what old school tricks did you pick up from someone else?
Wait, half a thou from a piece of paper? Paper is usually around three or four thou thick, so the drag is really telling you when you're squeezing it, not the actual gap. Still a solid trick though, you just have to know what it's really measuring. Works great once you get a feel for it.