How do I advertise the Shirt Designs I've created.?

So I created a Design for Shirts, Hoodies, Baseball Tees etc... but I don't have an efficient way of advertising them. My Borderlands related Design is here:

www.redbubble.com/people/ramo393/wo...

I'de really like to start making a profit! Thanks to anyone who has an answer!

Start selling and producing as required in your local area, use social media tools to promote. send samples off to people you think might be interested in what you do Skate pros, teams, create a video, pics in interesting places

Alternatively, buy small business marketing for dummy's by Barbara Findley