Posca pens are the best way to customise your own stuff. They are easy to use, really bright and they come in loads of nib sizes...
I've collected Posca pens for ages now. Since learning about pop art at school, I have loved drawing it. Posca pens are the best pens for pop art because they are really bright and they look professional. The first thing I decorated was my pair of trainers. Then my wellies. Then I did the shoe box that my school shoes came in.
Most recently I did the tiny shoes for my baby cousin, Mina. She lives in France so after I decorated them, we sent them to her. My Aunty Lourdes and Uncle Yan sent us a photo of her wearing them and she looked SO cute!