(we used pumpkin patterns, but you can free hand or whatever)
staple or tape the pattern onto contact paper and cut it out using an exact-o knife.
cut the top portion of the milk jug off large enough so you can put a tea light in there.
at this point you have to really think about which part you want to be painted, and which part you want there to be light.
get that part of the contact paper and put it on the side of the jug opposite the handle (we put ours over the corner, so, you cant really tell it is even a milk jug)
make sure all of the edges of the contact paper are smooth.
go outside and spray paint it. yeah...
carefully pull the contact paper off.
the paint that you dont want to come off may peel a little bit with the paper, go slowly.
pretty spiffy isnt it?
(sorry about the lack of pictures, i decided to make a how to halfway through the process)