The first time I gave my son a pen and a paper was when he was thirteen months. He grabbed the pen that I gave him and put something on a paper like a pro. He scratched and scratched as he liked. First, on the paper. Then on the bed sheet, on his arms and legs, his head. Finally, everywhere he wanted and he could reach.
Once, I chanted a children song while showing him the way I drew circles into a teddy bear: “Small circle, small circle, small circle, big circle, big circle, big circle.” He smiled and watched me carefully and seize hold of the pen. He drew as usual. Then, after a few times showing him drawing circles, he started drawing them with his own styles.
One thing for sure, he does not like being directed.