If there was any sewing notion that I believed should be a household staple it would be Fray Check. It is known most for its use in sealing the edge of fabrics to prevent fraying but it can be used for so much more than that. I have found that I tend to use Fray Check on most of my ready-to-wear store bought clothing.
For example: When I get a shirt that has buttons on it the first thing I do is put a dab of Fray Check onto the back of the stitches, on the inside of the shirt, which will keep it from unravelling the whole thing if I break one thread. (Honestly who actually keeps track of the extra buttons they attach to the tags?) If I find that I have a hole in my shirt I will also put a bit of fray check on the edges of the whole to keep it from getting bigger before I am able to mend it.
In my sewing I tend to find myself using fray check in tight areas that I am unable to overcast as well as using it to finish off a serged edge. Silk ribbon unravelling at the cut? Fray Check!
Comment below your favorite use for Fray Check!
Try it out for yourself!