You will need:

A canvas (you could also use thick paper)

Range of paint colours

Brushes

Masking tape

Stick the masking tape on the canvas in random lines so that it criss-crosses itself several times, creating a range of shapes between the tape.  Paint each shape a different colour.  Try not to have any adjacent shapes the same colour.  Once dry (I used a hairdryer) add patterns to each shape using a smaller brush.  The challenge is to use a different pattern on each one!  Allow to dry again and then very carefully remove the tape in the order you stuck it down.