I would commend to anyone reading this thread, a look at the close-up of the hands in Peggy Baumgaertner's "Unveilings" portrait of the
Consulate of Malta.
In preparing to begin a new portrait, I've been skimming Joe Singer's
Painting Women's Portraits (out of print but not impossible to find, a great addition to the library), in which he says, on the subject of hands:
"I urge every prospective portrait painter to devote all the time he can spare to learning the anatomy, symmetry, and configurations of hands, for they can be a fascinating addition to a portrait, or a dam*ing embarrassment.
"You can, more or less, fake your way through poorly drawn facial features by employing cheap tricks to lull the unsophisticated viewer -- tricks such as sharp catchlights in the irises, startling reflected lights in the shadows, or hard-edged exaggerated highlights. It's not that easy to bluff with hands. Even the untrained eye quickly perceives a lamely constructed knuckle or finger.
"Next to faces, hands are the feature by which the general public separates the poor from the skilled portraitist. They are worth all the study and attention you can give them."