If you're going to be in the business, keep a sharp eye for what people want. Take a look at the latest trends and styles. Are the 80s back in fashion, or are people getting tired of retro and looking for something more modern? Are there certain sayings that are catching on that you can incorporate into your design? It's fine to create what you want and what you like, but if you can cross that with consumers want and like, well, then you really have a potential for profit!