Remember the Gap maternity top from this post? As I mentioned in the post, the shoulder are a bit narrow for my taste. However, the top still seems modest when I'm wearing it -- perhaps because of the high yoke and the non-gaping armholes. However, those narrow shoulders don't really work if you prefer to keep your undergarment straps out of the public view. Which is something I definitely prefer!
Simple solution? I added my own strap guard to the inside shoulder seams (the shirt is inside-out in the picture above). I've used ribbon in the past, but this time I tried clear elastic from my cloth diaper making stash. I much prefer it to ribbon! It doesn't fray, and it's also stiff enough to avoid twisting or flopping while I'm trying to snap it in place.
If you're looking to do the same, here's how I did mine. I sewed one half of the snap (the bulkier side, not that it matters) to the side of the shoulder closer to my neck. The other side of the snap is sewn to the elastic. Then I snap the two halves together and measure the elastic, leaving about 1/4" to turn under. That's probably not necessary, but it seems more secure to me. With the elastic end folded under (which is very hard to see in the picture, since it's clear), I made a few tiny but not-very-tidy stitches along the folded edge. And there you have it!