The concept of marketing is pretty simple:
- Find out the type of human that will want to buy your t-shirts (is it an emo, a goth, a head banger, a jock, a techa etc)
- Find a way to reach that market as many times and as cost effectively as possible.
It doesn't matter how many visits you get, you could get 100 hits a day and never make a sale. On the other hand you could get 20 hits a day from your target market and still make lots of sales. If you don't know where your market is, find out.
Also, don't put your eggs in the one basket, try multiple approaches concurrently. A person may see your brand and not buy immediately. But after they've seen your brand 10 times they may only then decide to buy.
When you're starting out you will find most of your sales come from friends. So use a tactic I like to call relationship marketing. It's pretty simple, make friends with as many people as you can, whether it be through this forum, through social media, or at a nightclub. 90% of my sales come from people I have built a relationship with. Some of which I have never even met in person. People are more likely to buy from someone they trust. Build that trust and it can be mutually beneficial for both parties.
That's marketing 101 in a nutshell

I have more where that came from so if you want to discuss further just hit me up.
Regards,
Jason S