To wear this shirt, simply put it on like any other top. It's great for casual outings or when you want to add a military touch to your look. When it comes to cleaning, follow the care instructions on the label. Usually, a gentle machine wash with cold water is a good idea. Avoid using harsh detergents that could damage the fabric. After washing, let it air dry to keep its shape. As for sizing, always check the size chart provided. Since different suppliers have different sizing, it's important to double - check to ensure the best fit for you.