I press after I add each border, and I do a final pressing right before I put it on the frame to quilt.

Same here. I press just about every seam. It's a lot easier than trying to work with the entire quilt later.

Press & use starch to help control the borders.

I'd absolutely press and like earlier posts said, be careful not to *iron*.

AlWAYS do a final pressing before sandwiching quilt. I press mine on double thick towels with hot iron and steam with top side up. Do not "iron" but rather pick up iron and press then move iron and then press. This allows you to get top's block and seams really flat so top will be smoth and easier to quilt. Don't worry to much if seams are twisted since this will not show up when top is quilted. I have not found an easy way to do this! Also I always press seams as I go and still do final pressing.