How to Make an XL Shirt Smaller
If you have lost weight and can no longer fit into that extra-large T-shirt, you don't have to throw it away. You can shrink your shirt at home for a better fit. Exposing cotton T-shirts to high heat and moisture will cause the fabric to shrink considerably when the garment dries. This process will only work once or twice; there is a limit to how much you can shrink cotton.
Wash your extra-large T-shirt on the highest temperature water setting on your washing machine.
Dry the shirt on the highest heat setting on your dryer.
Wash the shirt again on the highest heat setting on your washer if the shirt is not shrunk enough.
Iron the shirt using the iron's high heat setting until it is dry to complete the shrinking process.