Select a good flat stone as your ‘canvas’. Scavange in the local forest for items that could be used as paint (be respectful of the Country Code though…) mix items with a little water, or boil down leaves etc. (Scouts on camp can do this) and simmer for a while to draw out colour.
Other option is to use a pestle and mortar or an old sieve/tea strainer.
In other words – great fun to experiment!
Official Aborgine art is dotted and usually based around an ancient story…
large flat stone (or just paper); scavanged items – leaves/fruit/mud etc; onion skins etc. can also be prepared or bought in advance; vinegar (some items mixed with vinegar will draw out different colours; pestle and mortar; old sieve or strainer