Use one pen of one color, or choose several colors and use them all.
Don’t try to make your doodles “look like” anything in particular, but if they turn out to look like one thing or another, that’s just fine.
Somewhere, somehow include at least 10 words in your doodling. They can be isolated words, or words in a sentence.
When you have finished, squeeze a title onto the page somewhere, and put the date on it as well.
Here is a more detailed version of these directions.