I personally haven’t tried any of the below methods so I can't speak from experience to how they work. In my mind, the most lucrative way is through building a REAL business online and providing your visitors with great value. However, after some thought, I decided to include these here because, quite often, the biggest roadblock for many is a mental one: believing that making money online is possible. From my experience, once you have made your first dollar, or even your first cent online, the world is suddenly a different color.
These are but a few guidelines on how you can increase your affiliate sales and continually grow your affiliate checks. Sure there can be a lot of other tips that out there, and if you think they would work, we won't discourage you from following them. What's important is that you be able to find a way to: attract more traffic to your site, induce your visitors to click on the ads on your site, and be able to promote your merchant's products even outside the boundary of your website. If you can do these, there's no reason for you to fail in affiliate marketing.
Selling T-shirts and other apparel is a pretty saturated market but the tools to do it are easy to use, which makes it very quick and cheap to get going. If you’re creative enough, or tap into the zeitgeist properly, you can also have a runaway hit. Even if your first 19 T-shirts don’t sell more than a few copies, your 20th might make up for everything.