Yeah, keep it simple. For instance, I don't even listen to music, much less have a TV *ANYWHERE* near me when i am reloading. No distractions. As JE said, do one operation at a time, complete it and verify it, then move to the next. Consistency, and good record keeping are they keys to quality reloads. By the way, one of the most common mistakes I have seen over the years is the desire to Hot Rod... don't do it! If your set up wont get you to the yardage with the drop and drift you want, get a bigger gun.
As for the brass, yes part of the Magic is in brass prep. A short cut on brass is to use Lapua. If you insist on doing it the hardway, measure neck thickness. If the necks are not consistent, then you can neck trim, but remember, less is more!! Do not get too zealous when trimming brass. Primer holes can also be checked for bur's, but for the sake of sanity and precision if you do decide to de-burr the holes, get a good tool and go *VERY* sparingly!!! When messing with a flashole Less Is More !! You can utterly ruin a perfectly fine piece of brass by getting mid-evil on the flashole. If you really want to get tricky, you can sort by case volume as well, but unless you are going for world records or something, that is probably a little excessive, as long as you use brass of the same make, year, ect..
Hope that didn't come off as preaching, but, been there done that got the tee-shirt!