Not much to add, that pretty much sums it all up. What I'd add is to number (10)
10+) Also decide beforehand if you want to work with a fulfillment service (like cafepress or printmojo) or if you want to do it yourself. If you do go with fulfillment check which company you want to work with by looking extensively on the net for reviews, research their products, learn about their payment methods, what shirts they use to print on your designs, what customers think about the company... PLAN PLAN PLAN!! It's extremely important to plan beforehand as it will give you a guideline on which to walk.
11) http://www.entrepreneur.com << learn to love it
10+) Also decide beforehand if you want to work with a fulfillment service (like cafepress or printmojo) or if you want to do it yourself. If you do go with fulfillment check which company you want to work with by looking extensively on the net for reviews, research their products, learn about their payment methods, what shirts they use to print on your designs, what customers think about the company... PLAN PLAN PLAN!! It's extremely important to plan beforehand as it will give you a guideline on which to walk.
11) http://www.entrepreneur.com << learn to love it