When I was younger I used to try to make these kind of drawings with paper, ruler, and a pencil. Now I've written a program in java to help create these images. They are clearest if you maximize the size of your browser.
squares swirly square sad face flat 3D surface
flower free bird full heart half heart
heart ring open star palm trees roses
sharp face slanting diamond smoother face snowboarding
spider more squares stingers stitched triangle
swirled cube opposite swirled cube hexagons and triangles three triangles
tiled oriented triangles tiled triangles opposite twists butterfly