Printing them yourself is done with heat applied transfers. In my experience they are hard to do right at home with an iron. You really need a heat press which is much more expensive than just designing the shirt online and having someone else print it professionally.
The first thing you’ll want to think about is if you’d like a slogan, a slogan with an image, or just an image. The pricing of custom t-shirts is usually based on how many colors the design you come up with. If you just have text with 1 color, it is way cheaper to print than say a photographic image. So if you are choosing to add an image, you’ll want that image to be as few colors as possible, unless you are ready to spend a lot.
Once you know what you want the shirt to say, you’ll want to start playing with fonts. Font selection can really improve the way the t-shirt looks. You want to choose something that is easy to read unless your goal is to have people staring at you for a while with a confused look on their face. Bolder fonts of course will print better, especially on darker colored tees. A custom tee with text that matches the graphic will be the best. So for example, you might want to pick a techno looking font for a shirt you are going to make about clubbing. Or you might want a computer font for a technical joke. The font selection for your idea is very important.
Once the shirt arrives, you are now ready to show off how witty you are. You can get hooked on making custom t-shirts, as all you may be the envy of all your friends with your intellectual prowess being shown on your chest. Wear your design with pride and get ready for the compliments!
We use a technique called DTG (direct to garment printing). There are a few companies beginning to specialize in this technology now and it’s advanced at an amazing pace over the past few years. Without wanting to put too fine a point on it (and I am over-simplifying here so apologies to the makers and inventors of the machines), it’s essentially ink-jet printing for fabric. And it has some great advantages over screen printing for us particularly.