A loofah sponge is derived from a luffa gourd after it has been dried. These sponges are used for exfoliating skin, and the right one for you to use can depend on what area of the body you would like to scrub with it. You may want to feel the sponge before you buy it in order to make sure it does not scratch your skin, or make it very red. These sponges can harbor bacteria, so it can be a good idea to buy one with a string on it so you can hang it up to dry when not being used.
You may want to buy a loofah sponge that has a long handle on it. One of these models can make exfoliating skin while you are in the shower very easy to do. It can be a good idea to hold the handle and then try to scrub your back with the loofah in order to make sure you are able to reach all parts of your back. If you are unable to do this, you may want to choose one that has a slightly longer handle.
A bath loofah might be purchased as part of a pedicure kit, and this might be something you need if you are looking to smooth the skin on your feet. One of these sponges might have a very short handle or a stick. The loofah end might be round or very flat, but one that is mostly flat generally makes it easier to remove dead skin on the end of your toes. If you decide to buy loofahs for your feet, it can be helpful to find ones that have a carrying case that allows you to store toenail clippers and nail files along with the sponge.
You can buy a loofah with a wooden or plastic handle; some smaller ones might have terrycloth or rope handles instead. Those with a wooden handle might be harder to hold onto than a plastic one is. Even so, one with a plastic handle might become slippery whenever you are using it in the shower. You may want to choose one with an ergonomic design if you plan to use the sponge for an extended time. If there is a wrist strap attached to the end of the handle, this could help you hold onto the sponge better no matter what material this piece is made from.