When I was a teenager, my step-mom made us tear the dryer sheets in half, using only half at a time in our laundry. This was smarter than I realized at the time. She also told me, some years later, that she re-uses them ("They're good for two dryer cycles", I think she said). I hadn't ever thought of that, and since then I've tried to make it very easy for my family to save them and use them a second time.
Here's what I do now: I have a plastic basket/crate container sitting above the dryer on a shelf. It looks like this:
The goal is to collect the sheets as they exit the dryer. Most days, though, I find them on the sofa where the laundry gets dumped, on the floor, and sometimes on top of the laundry room trash. Or tangled up in a shirt.
Once the basket is full and the dryer sheet box is empty, we reuse them until they're gone! Sometimes I put two used sheets in a load, especially if it's a large load or something like blankets or towels. It saves money!!