Many retailers now take orders online so you can provide your design to them using an uploading tool, and they will deliver the finished product to you. Screen-printed t-shirts are also cost-effective especially if you order them in bulk.
Screen printing clothing are highly effective marketing tools because of ease of wear. You can wear t-shirts at any special event (work or personal), sporting event, and even on top of your regular clothes. People do read what is on t-shirts as they pass by, and that provides great exposure of your new business or special occasion to a wide audience.
Screen-printing for advertising requires smart designing. Make sure your design is unique, simple, and can be read at a quick glance. Use fonts and colors that can be seen even from a distance. When designing your t-shirt on computer, keep in mind that the colors and contrast look different once it is printed on t-shirt than on the screen. Limit your designs to 5-8 colors at the most. Another point to note is that people should be comfortable wearing it to places other than the event itself. It becomes a great tool in popularizing your brand name in many different scenarios and as t-shirts are durable, the company name stays in memories for a long time!