I am still pretty new to reloading and even after loading several hundred rounds I have been trying to balance the amount I expand and taper crimp the case. Bullet setback has been an issue for me and I wanted to see what others would say in regards to how much expanding I do and how the bullet sits when I seat & crimp it. I try to expand as little as possible so as to retain as much neck tension as possible but then it's difficult to to set the bullet into the brass and get it to seat straight on. Am I just not experienced enough and need some more practice? Is there an art to it I have not yet learned?

The 'art" is really to follow the book in setting up the press. Expand the cartridge until your bullet will sit on the top with a little ring of space showing between the bullet and the case lip. Insufficient expansion prevents the bullet entering evenly and causes crooked bullets.
Your taper crimp should be about .003 below body size for a .45, for example. Revolver bullets get crimped into the cannelure, if present.
What specifically are you loading?

Added: It is important to use the correct nose punch on the seating die to match the bullet you are using.

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Science plus Art

Flaring the mouth of the case so you don't shave the bullet will not lessen neck tension. Remember, you are only flaring the mouth, not the entire case.

Seating the bullet correctly has already been addressed, make sure you are using the right seating nose punch for the bullet profile you are loading.

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SWCA #3437

Thanks for the help. I thought expanding the mouth of the case impacted the neck tension because it seemed like when I keep it minimal it solved some of my bullet setback issues. I also didn't think to change the nose punch which is did fix part of my issue. I'll switch it out and make sure I can set the bullet in straight and see if I still have any setback issues.

try a hornady seating die it has a collet to keep the bullet straight. I ran into the problem of canted bullets in 9mm was using lee dies. did manage to seat them straight but took two lee dies one that made a small seat while close the case mouth tight to the bullet but not so much as to crimp which gave the bullet no where to go but straight.
secent further seated the bullet.

Spartikus:

+1 on the Hornady seating dies. If you have enough flare to sit a bullet on the case, it will align it with the case prior to hitting the seating stem.

Another thing not mentioned related to your bullet set back issue is your crimp. You haven't indicated what you're reloading, so I'll presume for semi auto pistol. If this is the case, don't over crimp because this will result in decreased neck tension. Make a dummy round going through all dies. Remove the bullet from your completed dummy case and see if there is an indentation ring on the bullet at the top of the case. If so, consider decreasing your crimp until you get just a faint or no indentation.

If you are loading lead bullets, consider an expanding die like the Lyman M die. The reportedly don't allow your seating die to resize your lead bullets, which is the quickest way to bullet set back.

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CZ75B SR9

I had the worst setback problems with my .45 auto when using RP brass + plated bullets. RP brass was too thin and had insufficient neck tension, I think the bullets were slightly undersized. When I switched to Federal and Winchester brass, the problems went away.

One common mistake I see a lot is the advice that "crimp prevents setback". This is false. Neck tension prevents setback, not crimp. Excessive crimp reduces neck tension and makes the problem worse.

In an auto, taper crimp just enough to remove the mouth flare. I apply just enough crimp so that the cartridge feeds reliably, and no more. I think it worked out to about .471 or .472 in my .45.

+1 on Hornady dies.