While thinking about opposites, I stumbled upon the idea of the four elements and voila! Here there are three variations on the theme.
In the first one,a very rough draft I drew images than to me represented these elements.
In the second sketch, I condensed the elements to a minimum; then I placed them inside a square as if to make them fit a pattern. I like how it turned out, specially the quality of the strokes.
In the third piece, I decided to tackle the idea of the four elements using images and then adding some crayon touches. I think the free flowing composition works ok, but I prefer the second piece.