Discuss the process of getting your t-shirt line into brick and mortar stores and selling offline. Topics include industry tradeshows, events, line sheets, sales reps and other retailing tips and advice.
If you don't have a business plan now is a good time to start one. Set specific short and long term goals and how you plan to achieve those goals. Periodically check your list to see how you are doing. Its important to track you profits so you know what works & what doesn't work and also keep abreast of new trends (design & apparel wise). If I was selling popular T's on a web site or locally I would poll my customers & ask them what they want. I might set-up a contest with a prize (free T's) for the winning idea. A T-shirt blog might be a good means of generating some design ideas from your subscribers.