Selling T-shirts is great…but there are a lot of T-shirts out there. Instead of being vague or overly general, find a niche that you can focus on and stand out in. Maybe you're into the sci-fi/fantasy genre and can design some really eye-catching art that would appeal to other people who are into that. Or maybe you're a quick thinker and can come up with really funny quips and quotes about timely Hollywood gossip. Maybe you're a wiz with painting pictures of kittens and puppies. Whatever it is, find a focus and blow it out. You'll do better catering to a smaller but loyal audience who can look to you as an ongoing source of products each time they want to shop for something new.