Play in the dirt. Go outside and create something in or with the first patch of dirt you can find.
A few minutes into my walk home from work, there's an artificial lake. Since it's connected to the Rideau Canal, it's drained at this time of year and is a very nice, albeit rather large, patch of dirt. I walked along the edge of it until i came to a suitably muddy area – and this was more than mud, it was thick, grade-A mud, almost like thick clay. I grabbed a stick from the ground and hopped on wobbly rocks to draw this mini-maze... a complete throwback to my childhood: my mom, sister and i would spend many a cottage day on the beach at low tide, drawing huge mazes for each other to walk in/solve on the wet sand. I wouldn't try walking in this mini-maze unless you're wearing rubber boots!