Here’s an oldie but goodie. It’s particularly useful now that we are into the prom/cotillion/bridal sewing season.
When making a spaghetti-strapped dress out of heavy (or even mid-weight) material, I reinforce the straps by drawing drapery cord through the finished strap tubes. The cording is 1/16″ wide, so it adds strength without adding bulk. It also prevents the strap from stretching, which can be a problem if it’s cut on the bias or cut from a loosely woven or elasticized material. And it eases my mind about whether there will be any ’embarrassing moments’ while wearing!