I went with a green theme and a brown theme which falls in more of a wooded terrain.
The photos of the finished product are just below.
(This will give you an idea of the size of the nano geocaches)
(Is that a piece of bark I see or just some debris from that stump there. Couldn't be an evil nano geocache... nah.)
(Might be tree mold, a rock, anything but an Evil Nano Geocache.)
Here is a link showing then as they were being made.
I had a real blast making these geocaches and good luck to the winners at the Silent Auction.