You will need roller paper and paint that looks like this

And polystyrene
Step 1
Get your paper and draw a drawing
Step 2
After you have done get a sharp pencil and put your drawing on your polystyrene.
Step 3 then poke holes all around it then you well see it come out
Step 4 then your polystyrene will look like this

Then you can get the paint and roll over it then you can put it on your paper and then it will look like this

And now your done