Call me a prude, but I really can't stand it when my bra strap starts to wander, letting the world know just what color and condition said bra is in. (Answer: generally not great.) It drives me nuts. I don't want to have to constantly be adjusting and digging around. It's just not...dignified.
Fortunately for me, the solution to the problem is really simple.
All you need to fix your shoulder-centric wardrobe malfunctions is:
Ribbon 1/4" (7 mm) wide
two sew in snaps
matches (yes, matches!)
Start by cutting a 2.5" (6 cm) piece of the ribbon. Singe the ends with a lit match, so they don't fray. (See! Matches.)
Fold the ribbon in half, and give it a good pinch to press a crease in. (If you wanted to get all perfect about it, you could press in a crease with a cool iron. But that's totally optional, and frankly, a little overkill for this project.)
Sew the snap pieces onto each end of the ribbon like so:
Make sure that they're facing each other so you can snap them.
In the shoulder of your garment, sew the ribbon into place. Make sure the snaps are facing towards the arm.
Done! Now repeat the process with the other shoulder.
Now, when you're getting dressed, simply snap that pesky bra strap into the little loop. No more wandering straps! No more migrating necklines! Your life is really coming together now!
Now, go spill something. The universe hates a vacuum.