Individual Portrait
Wear something that you are comfortable wearing. Rarely should you go out and purchase something new for the session. Portraits should emphasize the face, even if it is a full body pose. Wear solid colors- solid colors are less distracting than prints or patterns, while they tend to minimize body size.
Group Portrait
The main purpose of a group portrait is to bring out the expressions and personalities of each person in your family or on your team. In order to emphasize the faces, it is important to minimize the attention drawn to your clothing. This is accomplished by keeping several things in mind.
Wear solid colors- solid colors are less distracting than prints or patterns, while they tend to minimze body size. (If necessary tiny prints are fine) Wear similar colors. Choose a single color tone (such as navy or charcoal) for everyone in the group. This prevents one person from "standing out" in the photograph. Pants and skirts should be as dark (or darker) than the tops. Pants that are lighter will make legs appear larger. Keep the shoes and socks dark, as well.
Ideally, long sleeves should be worn. Living in S Fl, this may be a problem but keep in mind, Short sleeves or sleeveless tops will add weight to the arms. The arms are usually lighter than the face and as such will draw the attention. The human eye is attracted to where light and dark meet.