mr_tom
I find that the thing to focus on is the vertical roundness at the beginning, and then focus on the side-to-side.
Actually, I think you should pay attention to both radial and lateral trueness throughout the process. Find the worst spot, make a correction and then move on. You never want to spend too much time working on one spot or type of trueness.
I think the hardest thing to get right as a newbie is balanced tension. Having access to a tensionmeter or an experience pair of hands to check tension can be a godsend.
Actually, I think you should pay attention to both radial and lateral trueness throughout the process. Find the worst spot, make a correction and then move on. You never want to spend too much time working on one spot or type of trueness.
I think the hardest thing to get right as a newbie is balanced tension. Having access to a tensionmeter or an experience pair of hands to check tension can be a godsend.