Quilters are probably always learning of new ways to do things, at least new to them and here are some things I've learned that have helped me tons...
Sandwiching and quilting: A guest on Alex Anderson's Simply Quilts (whose name escapes me now) showed how to sandwich a quilt smoothing the seams, borders and blocks square, pushing excess to middle. The quilting will take up the slack and your quilt will be square, and hang better.