Why not try and paint in a Cubist style. Set up your own still life – a cup, bowl and bottle for example. Draw these objects in blocks looking from different angles and arrange these blocks in different places around your page.
Like Norah McGuinness choose one colour as your main theme e.g. blue and colour your drawing in shades of blues. Compare Garden Green with works by Picasso and Braque. Your local library will have some art books with examples of their paintings.