Some of the simplest ones are just single shapes, circles, squares, ovals but they don't have to be boring.
This was created with just some ovals and is great fun for children to do in the holidays. Get a graduated look by sponging the paint on rather than brushing. (Although this was done with an airbrush, it doesn't have to be.)
It would be great, done in colours with fabric paint on T shirts. The same shape was used in different sizes to make these eyes
At the other end of the scale, another stencil was used to add detail to this reptilian eye...
I shall be making another new video very soon on making stencils, since it appears to be a popular subject and I have an idea or two....:)