Well, if you're serious about all this, some random opinions: Expect about 25% of the people who think something is a good idea to actually pony up when it comes down to paying real cash for it. Take this into consideration when deciding on methods of production that require advance payment and/or minimum quantities. To be truly effective, tee-shirt slogans should be based on some sort of wit that a non-Brust reader could appreciate. The "knife between the shoulderblades" quote is a good example, because Tolkein's original is reasonably well-known, especially after the popularity of the films. "Got Morganti?" is an amusing in-joke and might even garner a few appreciative nods at a con, but it's something that that no-one outside of the Brust-reading community would "get". The former would have a greater chance of making the viewer smile and possibly go to dreamcafe.com to learn more about it. It serves the double purpose of selling more tee-shirts and introducing new readers to Brust/Dragaera, whereas the second only caters to the inside knowledge of its wearer.