Supplies: Free motion machine foot here
If you want a unique way to customize your clothing, free motion sewing is a great start. It doesn't require an expensive machine, or loads of time hand embroidering. It's pretty simple when using a basic free motion foot here. It takes some practice but you basically just write or draw with the machine while moving the fabric with your hands. It's best to do this on tougher fabrics like canvas and denim. I've tried jersey or stretch fabrics with little success.
You can even create tags of your brand by using twill tape.
Customize denim, cotton shirts, or pillow cases.