These sweatpants are super easy to use. Just slip them on like any other pair of pants and you're good to go. They're great for casual wear, working from home, or light exercise. When it comes to washing, turn them inside out and use a gentle cycle with cold water. This will help keep the colors vibrant and the fabric in good condition. Avoid using bleach as it may damage the material. After washing, you can tumble dry on low heat or hang them to dry. As for sizing, always check the size chart carefully. Since different suppliers and brands have their own sizing, make sure to pick the size that fits you best to get the most comfortable experience.