I always use mattress stitch, regardless of what the pattern says. I think it's just the designer's preference for back stitch. My sloppy seams almost stopped me from knitting sweaters, but once I learned mattress, all bets were off.
For shoulders, I've gotten to the point where I always do a three-needle bind-off, again, regardless of the pattern. It just makes such a beautiful seam--another technique that makes me love to make sweaters.
"Trust the pattern!"
Time flies like an arrow, but fruit flies like a banana.
Hop aboard while we follow the cloud-covered van of knitting harmony, man!! Woooo!! --Hedgehog
IngridKH on Ravelry