You get to choose from a variety of shirts and stuff at character creation, but after that, you're stuck with it. It'd be great if someone could maybe make a wardrobe mod that lets you post-creation change what shirt you're wearing, with maybe future expansion to change pants.
You may use altar in wizard's basement after you have 4 hearts. Or use my mod that places this altar at the Seed's shop for easy access. http://community.playstarbound.com/threads/random-keytens-stuff-greenhouse-10x92.108551/