I made some labels with Shrinky Dinks (also called Krimpie Dinkie or polyshrink, shrink a dink etc). First make your drawing with a permanent marker. The seize I used was 10 x 18 cm (!), that will give labels of 4 x 7 cm(!). After doodling, I gave them some color with colored pencils. Then you have to bake them for about 3 minutes, but look on the package for the exact time. O, and don't forget to punch holes in them before that!!
This was the original drawing on the shrink folie.
These labels are fun to use with a handmade book or a present.