One of the best pieces of advice I read about sewing bras is to create a bra toile, however, I recently came across a bit of related advice that I find equally helpful. Create a bra toile of ONLY the band. In most cases - especially true if you're fitting yourself - the band will fit fine and/or remain the same. Its the cup shape/design/size that differs that will require multiple adjustments. The fitting band should be complete - with elastic, hooks and straps. That way, you only need to make a toile of the bra cups! Easier to sew, try on, take apart and repeat as necessary.
Here's a pic from the Merckewaerdigh site: