To use these leggings, simply put them on like you would any other pair of leggings. They're great for yoga, but you can also wear them for a casual stroll around town. When it comes to maintenance, it's best to wash them in cold water on a gentle cycle. Avoid using bleach as it can damage the fabric. Hang them to dry to keep their shape. As for sizing, the leggings run true to size, so pick the size you usually wear. If you're in between sizes, you might want to go for the larger one for a more comfortable fit. Also, don't forget to pair them with the Studio zip - up jacket for a complete look.