Put some paint (thick "blobs") onto one half of the drawing paper.
You can move it around with a popcicle stick. Don't mix!
Contrasting colors work great together.
Fold the paper and rub it to move the paint to fill the gaps
Open it up.
Let it dry for a few hours (to make sure it is completely dry).
Place the viewfinder over the painting.
Trace the areas thet you like.