Even my 85 year old mother who is blind in one eye and can barely hold a pen is covering her scratch pads with doodled art. It's as simple as drawing a shape. Add two criss-crossing lines to connect all sides of your shape. Then pick a design--like small circles between wavy lines--and fill in one section of your shape with the repeated design.
One section by itself isn't all that impressive but when you see four doodled designs in one shape, you will marvel at your own genius!