It is definitely a good idea to design your own shirt. You can, this way, design your t-shirt the way you want, have all sorts of creativity embedded on it. For those who are creative, it is a very thrilling prospect, actually.
T-shirt designing is easy, however, it does require a little bit of creativity. It isnt as simple as putting together a few pictures, some colors and a bit of text. You have to get it pixel perfect if you want the t-shirt to look good. You would be better off buying t-shirts rather than creating them on your own, if you are unable to do that.
There are a number of websites on the Internet where you can literally upload your design (art, text, etc) on the choice of your t-shirt. Then, choose the color of the t-shirt, its size and the material its made up of. Once all is done, they will deliver the t-shirt to your doorsteps.
It doesnt get easier or better than that. If you want plain text, you have the ability to get that printed over the t-shirt, in any font, in any size, in any color! You can customize the t-shirt to your liking. You can do whatever you want to do with the t-shirts. It is an exciting process too!
You may use these t-shirts on a number of occasions. You may gift them to your loved ones on a birthday, or on their anniversaries, or as a memento. It will be something the other individual will remember for a long time since its personalized. It also clearly shows the work that went into creating the t-shirt.
Dont purchase anything on the Internet before you have checked their reviews though. Find out some forums and/or blogs to check reviews. Research is very important, more than you think.