The customer analysis section of your t-shirt business plan must detail the customers you serve and/or expect to serve.
The following are examples of customer segments: college students, sports enthusiasts, soccer moms, techies, teens, baby boomers, etc.
As you can imagine, the customer segment(s) you choose will have a great impact on the type of t-shirt business you operate. Clearly baby boomers would want different product options, and would respond to different marketing promotions than teens.
Try to break out your target customers in terms of their demographic and psychographic profiles. With regards to demographics, include a discussion of the ages, genders, locations and income levels of the customers you seek to serve. Because most t-shirt businesses primarily serve customers living in their same city or town, such demographic information is easy to find on government websites.
Psychographic profiles explain the wants and needs of your target customers. The more you can understand and define these needs, the better you will do in attracting and retaining your customers.