I love doing these! A 20 x 16″ oil study, done as the first exercise in my portrait class. Starting with the biggest color masses of background, a general flesh tone, and hair, I worked towards the smaller masses, using the largest brushes possible, solid painting, and avoiding details of the features.
The whole idea is to teach oneself to work from the general to the specific. The neutral gray background and black outfit give a value range against which the flesh tones can be measured. It’s a great way to appreciate how much the likeness is in the greater shapes.