With bindings, I pin only the corner fold on the front when turning to keep the miter square. When hand stitching the back, I pin parallel to the fold with the pin heads to the right, closest to the hand with the needle, so I don't get stuck.
For sewing blocks and other parts of the quilt, I pin often. For me, it guarantees accuracy and I seldom have to unstitch anything. I use Dritz extra fine glass head pins from JoAnn's.
http://www.joann.com/dritz-quilting-...pk/xprd274427/