There are many different methods and effective marketing strategies that you can try to increase traffic to your online store, like a Teespring store. Some of these popular methods are: 1. Offer unique products and make sure that there is a market for such products.  2, Start a referral program as a good mouth-of-word can take a business to the next level.  3. Focus on Search Engine Optimization (SEO) to increase organic growth and traffic.  4. Digital marketing, especially social media marketing, through platforms like Instagram, can help you expand your customer base and make more profits.  5. Provide quality content on the store in the form of attractive photos, videos, and blog posts.