Shooting for Sales?
How you pose your subject (or not pose them) really depends on what your actual goal for the image may be. Formal headshots are typically used for identification for a variety of legal and business purposes and your subject is typically looking strait at the camera typically with flat lighting with the subject essentially filling the frame. Certainly there is a market for this, particularly in the business and entertainment world. Glamour and Boudoir images typically have a client looking directly at the camera as well, occupying the majority of the frame with the goal of being very appealing to the viewer. A market obviously exist for these images not only for individual clients, but to fans of the style of photography. Clearly wedding photography is a genre until itself and has the most meaning to the wedded couple. But sales to the general public, certainly to hang in their homes the approach may be slightly different..
To shoot for sales to the public usually has a slightly different twist. Unidentified subjects in many cases will sell better. Not many people will want a stranger hanging on their walls unless of course it is some iconic figure. Shooting subjects that cannot be easily personally be identified typically has a better chance of sale to the general consumer. In many cases, a spouse does not want a sensuous image of a stranger plastered on their living room wall.
Some art lovers will still post certain images will post images that may inspire them, or find them appealing in some manner, such as a subject looking away from the camera. We may seek distant images of people on a mountain top or even an subject playing a mythical creature. Often the subject is a smaller part of the larger image such as with a landscape or seascape.
There are of course abstract images, that some collectors within the general public may choose to purchase, which tend to represent some sort of altered reality.
Speciality collectors will certainly seek out images of their particular interest, and people in business may be looking for a particular type of image for a very specific project. That said, photographers who are successful in selling to the general public may require a certain approach that appeals to a wide audience. References for stock photography may be found on sites such as Shutterstock. Artists such as Brooke Shaden are very active in the education process for those wishing to hang art in galleries.