I often use Adobe Illustrator to doodle, to make an image with no plan in mind, just play around with shapes and color and see what happens.
For this illustration, I set up a few simple rules for the doodle. The format was 6x6" so I began with a blue square. Then, since I wanted it to be a face, I began with two circular eyes. After that, I made a drop shape to use as the only shape for the rest of the image. I could re-size this shape and rotate it, but I could not distort it, redraw it, or crop it (cropping could occur if the shape extend beyond the format edge). The palette was limited to three values, white, black, and blue as the middle value. My final rule was to create a left/right symmetry to reflect the symmetry of the eyes and the left/right symmetry of the drop shape (not counting the eyes, this rule was broken once, can you spot it?).
Again, I had no plan for this, other than a face. Would it be a human face? an animal?
an odd-looking man with a mustache?
a clown or masked wrestler?
But, eventually, what began to appear...
...was a tiger!
a decorative tiger!
with a winged one-eyed bug on its nose!