Find a colour that appeals. (In the example I have used a traditional watercolour paint ultramarine) Paint from the bottom to the top to produce a graduated wash diluting with water to get three different concentrations of colour. To get the water to flow, wet the paper beforehand, known as wet on wet, to give a basic landscape composition, with foreground, middle ground and background. If you love a colour enough it holds itself and the attraction is in the simplicity.
As it is hard to find only one favourite colour I created this picture ‘burnt Sienna’, straight from a tube of paint.