I learned to quilt watching Eleanor Burns on Sunday afternoon. She (Used to) make her blocks a little bigger and trimmed them to size. After almost 30 years, I still do this. I like to use the Creative Grids log cabin rulers for this reason. You can view their videos on YouTube to see this technique.
When I taught quilt classes, I told my students that I wasn't a perfect piecer. But I knew how to make it look perfect.