If you are a long time reader, you know that I am a huge fan of the plain t-shirt packs that you find in the boys underwear section at Target or Wal-Mart. When you buy them in the multi-packs they come out to around $2.00 a shirt. Boom!
I used E-6000 to glue these on. It says that it works on fabric. I’m not sure that I would just throw the finished shirt in the washing machine though. I would hand wash it just to be safe. As with most of my crafts, these are not going to be heirloom quality. Your kid will outgrow this shirt super quick anyway so if a jewel falls off, either glue it back on, or let them keep falling off and create a new design. Or un-design.