I designed the mural for my sisters bedroom. The drawing was done in Illustrator and then projected on the wall using a video projector.
I traced the outline with a pencil. And then started filling it in making sure the pencil marks we're covered. I used artist paint brushes for this. It took about 3 coats to get the color right.
I used lacquer paint because it was a leftover from a different project but I would advise people to use emulsion or acrylic paint for a smoother finish (with lacquer it's very hard to get rid off 'stripes' from the paint brush.)
[Thanks to Caroline of Carrie Can]