|Who are you targeting? The more sifepcic you are, the easier it is to find attract your target audience.For example, let's say you're doing t-shirts for toddlers. Obviously, the toddlers won't buy it themselves. But think about parents and relatives. What else do toddlers need hats? shoes? diapers? This leads to ideas for co-marketing, teaming up with another business that sells those things to your market.You're wanting to do this online. Do you want your own website, fulfilling orders or are you looking to upload your designs to a site and allow people to order from them (along with other designs)? If you're fulfilling orders yourself, you'll need traffic to your website. What are people searching for? You'll need to identify keywords that people search on, figure out how to get organic (i.e., non-paid) links. If you want to do pay-per-click traffic, that's easy, but'll cost you a little money. If you want to simply upload your design and wait for people to find you, then use a service like CafePress, etc.To build interest (inexpensively), you'll need to get pictures of people wearing your designs. Create a video with your performers wearing them. Upload pictures/videos to the usal places (YouTube, etc.)Social media sites can help as well to create buzz . You'll need pictures to have people see what's so wonderful about your designs. Find sites that have people that are your target market, and start blogging about your designs (appropriately).That should get you started.