Fold Over Elastic is a decorative elastic that comes in a variety of colors. Fold-over elastic can be identified by a small ridge that runs down the center of the elastic so the elastic can be folded in half. This elastic does not lose elasticity when sewn. It’s perfect for encasing raw edges, making it a popular choice for finishing and adding elasticity to undergarments. It can also be used for to finish armholes, necklines, and lingerie or knit garments. I never had an opportunity to used fold over elastic but suggest you give it a try! The variety of colors would be fun to work with. The internet wasn’t around when I started sewing skimpy.
Clear Elastic is a transparent and lightweight type of elastic. Clear elastic can be stretchy but beware of cheaper varieties as they can break easily. I recommend buying a better quality because you get what you pay for. Clear elastic is great for stabilizing and gathering lightweight and medium-weight knits. Clear elastic could work great for ruching if you find a quality brand. You might use clear transparent elastic for bra straps and much more.