I used the iron on interfacing for making letter shirts. It is double sided and works great. Another way to do it is to "finish" the edges of the letters with hot glue before you use the webbing/interface. I think its fun and you get to use any cute fabric you find (and its cheaper). Definitely try it. Its fun
Sewing works as well and it isn't too hard so if you can find someone to teach you, you can try that out as well.