Guess I'm the lazy one. I do a side, any side, then the next side, and then the next side working around the quilt ending where I started. However, I use more care when I am making a "better" quilt and then I usually mitre.

Suz

Sides first, then the pieces don't have to be quite so long on the sides of the quilt. Unless I'm mitering, then actually I probably sew the sides on first out of habit.

I do top and bottom first usually. Depends on the size of the quilt, and the look I want. The less joins the better is my motto. :lol:

Sides first for me also. Always have done it this way, except one time, and I just didn't like the way it looked. So I am sticking to sides first.
Personal opinion :D.