Lately New Kid has been demanding that I make letters on his drawing paper. I think this is from seeing his big brother write, but also he is very interested in identifying letters these days. I didn't want New Kid to start expecting me to draw for him, I wanted him to explore scribbling.
I stopped making letters and said to New Kid, "let's do it together!" and then started making crazy noises while scribbling. He thought it was great fun and joined in.
This idea came from Susan Striker's Young at Art (affiliate link). I couldn't find the exact quote, but if a child is insisting on the parent producing something recognizable on the page Striker suggests scribbling while making a noise such as "Firetruck! Whooo-weeee-whooooo-weeee!" If you are interested in ways to encourage creativity and the artistic process in your child, I highly recommend Striker's book. Actually, I view it as essential reading.