Some other observational drawings are:
Things in your pockets
Your purse and /backpack/jewerly
Their jackets, shoes, (in other words things they bring with them)
Art supplies set up into a still life (bottles of paint, brushes, palattes,
An interesting corner of the artroom
The lockers in the hall
The classmate opposite them
Their hands (I have them trace their hand first and create a surreal hand
(Left brain) and then they draw their hands in 7 different positions, cut
them out and put them on construction paper in an interesting manner. Some
have showed them sign language and had them draw their name in hand signs.
Things from nature like pine cones, leaves, flowers, branches, etc.
And the list goes on. Hope this helps.
Teresa in El Paso