It's said that art is driven by an intuitive impetus. That may well be for certain forms of art like the abstract. Some of the most powerful abstract art is created by small children, and certain highly intelligent animals who can understand the brush as a tool to hold in their mouth or trunk, dip in color, and splash onto a canvas. The brush simply runs wild in a riot of strokes and color. I believe that any art that isn't constrained by a certain system of discipline, practice and consistency that runs through it is purely intuitive. It may be unimaginably wild and forceful, like the art of an autistic savant; but it is merely the result of a visual train of unconscious action; impelled by raw nature, rather than by purposeful and controlled thought. A beautifully turned out oil painting, drawing or watercolor, however, combines the intuitive process with rigid discipline - incredibly difficult to accomplish since one must give the illusion of spontaneity while sticking to multiple rules. My firm belief is that without these rules the effort at outstanding portraiture will always fall back into the abstract.
My traditional disciplines for portraiture are pencil and pen/watercolor. For this blog I'll stick to the discipline of the pencil. One stark rule - there is no shortcut to awesome pencil work! The portrait artist must master the right way to wield their pencil. Complete control of this awesome tool depends on how you wrap your fingers around it. All of the art is made up of fine lines, the lightest graduating to the darkest. A serious student will hire a tutor, at least in the beginning, to map the proper path in their brain. The lines must basically head in one direction; for the right handed, from left to right. The left handed artist will work from right to left. With many moons of practice will come the freedom to stray successfully from rigid rules. After all, this is not a graph.
As a young student in art school I well remember one of my best teachers telling the class that "if the work is beautiful, even if not technically accurate, then it is right". Looking back on my experiences I would swear by his words! A great mistake a pencil portraitist might make, in order to skip steps and save time, is to smudge with the finger(s). There is no surer way to create an ugly, amateurish looking piece than to smudge. I don't care how many touted artists have smudged their way into fame. Hands down, their work is unwaveringly bland - even worse - lifeless! I beg my readers who would like to learn to draw - please take the high, if more difficult road, and avoid becoming mediocre.
For a portrait artist there is always the trap of disproportion from one side of a full face drawing to the other. I have no fast answer to that. I myself have fallen into that quicksand pit. Many, many ancients did so as well. My most trusty device is a hand mirror. Even the most initially admired work can reveal significant flaws through the mirror's unwavering reality. When the Wicked Witch of the Snow White fairy tale strove to influence her mirror she was unable to. It was unforgivingly accurate. Old Masters have used this trick, and it really works! Don't be afraid to use it too. You can then see your work objectively, and correct the flaws.