Almost exactly what my body/paint guy said when he was about 6 months into my Dart.
A trick he found that he said helped him a lot was cutting the retractable metal tape out of a 25' measuring tape and then taping in to the side of my Dart to use to establish laser-straight continuous body lines. Do this after setting all the gaps.
One of the previous clowns that attempted to do body work on my Dart attempted to work the body lines with the front fenders and doors off of the car. Needless to say the lines were all over the place and nothing matched up.
