OK there are lots of ways to skin a cat but I'll take out my knife first.
I like to use a Lee Collet Neck Sizer and a Redding Body Die combination. The Lee Collet will size the neck with no lube, no expander ball jerking on the neck and with very little runout. The Redding Body Die will size the case body and push the shoulder back if needed.
IMO it is important to size the case body for 2 reasons:
1. Mainly the brass in the case body can be banana shaped and if you don't size it so that it does not bear on the chamber, then it will push your case so that it may not orient the neck and bullet in line with the bore. Also if the centerline of the case neck is not aligned with the centerline of the case body then you may not be orienting your bullet in line with the bore.
2. Also chambers are not perfect and unless you can chamber the fire formed case body in the exact same orientation everytime then you may get a different orientation of the neck and bullet in line with the bore.
I also set the shoulder position for very slight contact between the case shoulder and chamber shoulder, called a slight crush fit.
To help orient the neck and bullet in line with the bore, I also leave part of the fire formed neck unsized
I do this by putting a washer around the case on top of the shell holder with the Lee Collet
If you are using a bushing die (which I have for a couple of calibers) then you can adjust the die to size only part of the neck. Then use the Redding Body Die.
So the case body is not in a bind in the chamber and the fire formed portion of the neck and the sloped shoulder contact orients the bullet in line with the bore.
Just my way, next cat up for skinning