To use this Ridgeline kids' performance tee, simply put it on like any regular shirt. It's great for all kinds of outdoor activities such as hunting and hiking. When it comes to maintenance, machine wash it in cold water with like colors. Avoid using bleach as it may damage the antibacterial and wicking finishes. Tumble dry on low to keep the fabric in good shape. As for sizing, always refer to the sizing guide in the photos to ensure a proper fit. And remember, the sun protection works best when the tee is in good condition, so take care of it to stay safe under the sun.