The easiest(fastest, may not seem correct to some) way that I have found that works for me is as follows:
Get factory ammo with good brass(the kind that you want to reload in) for break in of new rifle. Shoot and do the cleaning process for break in(your personal preference on procedure). You just fire formed your brass for THAT rifle.
Preparing brass: can be as in-depth as you want to make it! This is how I do it.
Trim all brass to same length, debur, check flash hole, clean primer pocket, neck size, insert primer, powder, seat bullet (I prefer not to have my dies set to crimp the neck of the case to the bullet-personal reasons), shoot
For most of the powders that I use on my rifles I have never found one that shot its best at min. load. I start projectile just barely off the lands. Start with powder a little above recommended min. but not by much. Start loading up one in small increments to signs of pressure. The last round that did not show signs(several verifying follow up shots) is the max for that rifle. Back off of the max (a fair bit,how much will be personal choice). At a constant powder load, I prefer 5 shot groups at 200-300 yards, start backing the projectile out of the lands a couple thousandths at a time. You will see the pattern large going smaller then increasing again. Go a few past to make sure. After finding your seating depth now start playing with your powder charge, again I prefer 5 shot groups at 200-300 yards. I found (with the powders that I normally use, coming from lots of trials) that it is better to start some where above recommended min but below mid range, working up in bigger increments to max charge. again you will see that the grouping will be large, get small, and get big again. Looking at your best grouping start working both ways in very small inc. to find the sweet spot for that bullet and powder at that temp. Make sure that you are looking at your brass. It tells you a lot. Your best load when it is 110 in the summer may not be your best load in the winter when it is 35 below.
Do some playing and have fun, but be safe!
Good Luck
