I made the shape with scotch tape. Painter's tape might work better. I did have minor seepage of the crayon so I covered it with gesso. Then I painted everything on. This is the tutorial I followed. http://daughterofgallifrey.wordpress.com/2012/06/18/doctor-who-crayons-zomg/
I did use a heat gun, like an embossing gun. Melts much better than a blow dryer. Also, I got the blue crayons from Target. They have small packs of all blue. Surprisingly, I have a big pack of crayons and pulled all the blues out and there wasn't that much. I just used the cheapo acrylic paint from Walmart. I also bough a multipack of different size paint brushes that also included a few narrow foam ones which I used to paint the blue on the tardis.