Suspenders go in and out of style for fashion, but in our house they never go out of style as useful tools. Between the double clipped ends, the long elastic length, and the adjustability, they are invaluable to us.
We took an inexpensive pair of suspenders and removed the metal slide that held them together in the back by clipping it with wire cutters - if the suspenders are sewn together, just pick out the stitching. Then you have two very long lengths of elastic with clips on both ends.
We used these to hold towels on the vinyl bench seat in an old station wagon instead of slipcovers, and just stretched them diagonally across the back of the bench, clipping beach towels in each corner.
After we sold that car, we then used them stretched from corner to corner underneath an air mattress to help keep the sheets from popping off the corners. We never had guests complain that the sheets came off the bed!
When we covered our sofa with a slipcover, we used a pair to help keep it from sliding up in the back. they are clipped to the slipcover in the back, and to the original "skirt" in the front, stretching underneath and holding the slip cover in place better.
Now that we have a toddler, and a table top that really requires a constant tablecloth, we stretch them from end to end under the table to keep our son from pulling down the tablecloth and everything on it.
So next time you see an old pair of suspenders at a yard sale - or find a pair in your drawer - think beyond fashion to what they can be used for.