This step can be difficult. It can throw the artist and also the subject if they see the image at this stage. But many portraits are painted with no foundation or understanding of how to ‘build’ a three dimensional portrait on a two dimensional canvas. As you put time into getting a good likeness, allow your brain to see what it needs in order to look true and. Correct when finished. Correct at the earliest possible stages and keep your marks transparent ,as light as possible. Then you won’t be fighting those heavy darks as you continue. I often make a correct mark on top of a not so good mark. It is only possible because I keep these early, structure building marks thin and light. Happy painting.Diana.