What most people do not know is that if you approach watercolour portraits with an open mind, the results can be quite stunning and surprising.
Draw out the subject lightly – rather than on the finer details, pay attention to the light and dark shapes in the head and face.
Use the dark washes first to block in the darkest values. Squinting your eyes would help you to isolate the dark values.
Block the lighter values of the face using lighter washes – make sure to leave the lightest areas untouched. Use plenty of water in your washes in order to avoid oversaturated colours, and make sure to tone down your warm washes to keep them from becoming overly intense.
After using the lighter washes, it will be easier to see where the first washes can be darker. Re-establish the darkest values using a higher ratio of pigment to water.
As the last step, fill in the background. One can see in Sri Lankan art that are available at places such as Sri Lankan Art Gallery that even the background has been given detailed drawings. Attention to detail should be given at this point where you can use a fine nib brush to add in the relevant details to finish the painting.