I take a measurement on my fired case using the shoulder datum line on the case. I'm looking for a Max .003" bump back. Any further is pointless and will wear your brass out quicker. Plus probably put your round out of specification. I shoot for a .001"-.002" shoulder bump. Once I have that dialed in to my die, I typically don't touch it. Just measure and adjust as needed. Also it's a good idea to adjust your expander ball at this point. After resizing a case, measure the neck diameter, zero out your calipers and then seat a bullet. Measure the neck again and hopefully your neck tension measurement will be around .0015" -.002" Polishing the ball might be necessary to get your neck tension right. Or you can always utilize a bushing die for resizing.