My little guy taught me a fun lesson which might be well known, but not in our house. If you draw on a sliding glass door or window.
It wipes off with a wet sponge.
When I walked down the stairs and saw the artwork on our window I said "draw on paper", but then I recalled reading that a child drawing with marker on his belly is not the child being naughty, but the child learning about his body and about his world. I have two people who sit on my shoulder, the parent, and the Early Childhood Educator. At times they agree, and at times they disagree. I am glad both sides came to terms with this fun activity.