I do my work in stages. As I'm using a single stage this makes the most sense
I'll deprime several hundred cases at once, then tumble them. Next up is resizing which I'll usually do 100-200 at a time. I'll then rinse them clean, and tumble them again. Next I'll trim to length at least 50-100 possibly more if I'm on a roll. Priming is then done with the primed cases stored ready for loading. When I load I do groups of 20. All powder is scooped, then trickled to weight, then funneled. I then work from my "loading block" ( a cut down styrofoam piece). I set each bullet fresh from the bullet box, and each completed round is put in the case.
I normally adjust my bullet seating die off a dud round I loaded and marked with OAL previously. I'll mic the first one or two to make sure I've got it right and go from there.
I use a charge of varget that is physically impossible to double charge with, heck it's almost a compressed charge just loading it once
Far as habits go:
I only pour enough powder out to fill 20 cases, the jug is then sealed and placed back in the cabinet. Same with primers, I only do 20 primers (what Lee says you can safely put in their autoprime) at a time.
My scale is located so that unless I bend down to check the pointer, I'm a little off (probably .5-.8 gr) low though. I'd much rather under charge a case by a little bit then over charge.
I made a series of dud rounds at the necessary OAL's and marked the outside of the case. Now if I want a a particular OAL (say for loading 77gr SMK for the 300 yd line) I can just stick that sucker in and set my bullet seating die.
-Jenrick