If you've got a printer, you can print off the sheet below, but if not, you can draw 30 circles (or as many as you like), on a blank piece of paper.
Then draw something different in each circle. It's as simple as that!
The possibilities are endless!
For younger children, you could do less and/or larger circles if you think they need it, but this activity is suitable for everyone, even adults could have a go!