This section is from the book "Complete Self-Instructing Library Of Practical Photography", by J. B. Schriever. Also available from Amazon: Complete Self-Instructing Library Of Practical Photography.
232. The first essential in all portrait work is to secure proper effects of lighting; therefore the student should become thoroughly familiar with the instruction given in the preceding chapter before paying any particular attention to detail work when posing the sitter. Allow the subject to appear as natural as possible, and direct your efforts to holding their attention by talking to them. When you are able to correctly light the subject and secure properly exposed and developed negatives, you may then give special attention to posing the arms and hands, as well as to arranging the drapery, turning the head at different angles so as to produce the best effects, etc.
Arms And Hands. With the lighting, exposing and developing accomplished, your attention should next be directed to the arrangement of the arms and hands. Whether the subject be a man or a woman, special attention should always be paid to the placing of the arms and hands, as their position governs the general balance in the portrait and controls the lines of the drapery. Even though a bust portrait only is being made, it is essential that the arms and hands rest easily so the shoulders will be squared and the sleeves and drapery arranged to hang gracefully. This is best accomplished by resting the hands on the lower limbs, midway between the knees and hips. If they are placed on the lap or on the knees the subject will appear round shouldered. If they are allowed to hang at the sides the shoulders will be thrown back too far, thus appearing drooped.
Wrinkles In Drapery - Men. If the subject is a man and the coat fits badly, having objectionable folds over the shoulders, place a wad of paper or a handkerchief under the coat directly beneath the wrinkles, and this fault will be eliminated. Be sure to pull the coat down in the back, so the white collar will show, also adjust the vest. If a scarf-pin is worn, or the watch charm shows, arrange them to prevent the catching of strong light, which will cause a conspicuous appearance in the picture.
Women. When posing women your attention should be directed to the arrangement and the lines of the drapery, especially the sleeves, waist, collar, etc. Objectionable wrinkles should be unobtrusively smoothed.
Height Of The Chin. The proper height of the chin is vitally important to good portraiture. For the ordinary subject the chin should rest a trifle above the level, providing the camera is placed at the proper height. If the nose has an upward turn care must be taken that the chin is not raised too high - rather lower it slightly. This will give length and tend to straighten the curve. If the nose is of a drooping variety, raise the chin a trifle above the center, supplying length. Raising or lowering the chin must be done in a natural manner; see that the subject does not extend the chin forward or draw it in. The head should be naturally raised or lowered, or tipped to one side a trifle.