Portraits are not born, they are made. They are created in the mind of the artist from portions of the subject, experiences, lighting and composition. Some general parameters should be set early on.
A somber, serious mood is enhanced by dark background tones, contemplative expressions, loose low-toned clothing, and deep, but open shadows. A happy, carefree atmosphere is set more convincingly with light, airy background tones, piquant expressions, pastel casual clothing and soft, ubiquitous lighting.
Props should be kept to a minimum. Allowable is anything which will support the mood and which will not detract from the main subject. A high key portrait can be enhanced with a white wicker chair, a loose white flower arrangement out of focus in the background or a high-keyed landscape judiciously placed off center, blending with the other background tones. A large, dark sculptured bowl of red apples, a black poodle, or a dark-toned piece of furniture in the background would contrast too sharply with the generally light toned subject and background. Attention diverted to these items due to their strong intrusion in the composition is lost to the main subject and detracts from the ambiance.
Attention should be paid to the lines created by the subject and other components in the composition. Lines leading strongly out of the picture should be avoided. Rather use curves to bring the eye back to the main subject. Moveable items in the composition can be place to complete gap in a leading line so as to facilitate the eye in its movement around the work. Invisible paths of light can be created with the use of similar colors, a repeated pattern or item, or the play of light and shadow along an edge. Where possible choose components with care, preferring meaningful items which play a part in the life of the subject, rather than an object chosen solely for its shape and color. For instance, if the subject is a potter, choose an attractive urn instead of, say, an antique doll which has no place in the subject's interests.
The light that falls on the subject can be used to support the mood. Natural window light suggests an old master genre and the sharp golden rays of a small source of light created the highlights necessary for a mood with a positive spin. Any available light can create a beautiful portrait if the direction and ration of light to dark is controlled. Reflectors add light to a dark, shadowed area, scrims or shades can tone down a too-strong source. The direction or the main source of light should enhance the features by sending light into the eyes, outlining the jaw and cheek, and finding the proper areas to highlight. Additional highlights are supplied with back or side-back rays of light, as long as their effect does not invent unwanted facial highlights or block up needed detail. Pure rim lighting is fairly safe if used with care.
Forward planning a portrait gives the artist an important edge toward making a successful portrait. Proper clothing, location, time of day, weather and needed props go a long way in helping the artist concentrate on the critical tools present in the mind of the artist.
I search every face for strong and weak points.