In terms of guidelines for all family photography, studio or outdoor, all members of the family should be dressed to the same degree of formality or casualness. Typically, solid color clothing of the same tone are recommended. Avoid the look of one person standing out because of a bold, distracting pattern or a contrasting light top when everyone else is dressed darker. Clothing should be classic and timeless that will not date your family photography (solid colors are best – no stripes).
For more formal family photographs avoid t-shirts, sweats, and tight short skirts (sometimes people are seated on the ground). Also, this is not the time to experiment with a new hair style or extra makeup. Use makeup to cover blemishes if possible. Babies often spit up; bring them a second outfit if possible.
Things to avoid:
Clothing extremes. Generally, turtle necks and v-necks are good, as long as they don’t over-power the subject’s face. Bottom line, the subject should dress to feel comfortable.
Bare arms and legs where possible. Opt for long-sleeve shirts/blouses rather than short-sleeve. Women should wear pants, a long skirt, and/or dark stockings.
Bright reds and orange (they battle the subject’s face for attention). Darker colors are generally better than light colors. Colors like white, yellow, and pink tend to over-power the face and make the subject took too pale. In general, the best colors are medium shades of blue, green, burgundy, and rust.
In summary, it is important to choose outfits that will make pleasing portraits, and be coherent with the style of portrait you are planning. Remember that busy patterns, stripes and bright colors are distractions from the focal point: the face, or faces in the portrait. Color coordination lends harmony. While all clothing does not have to match, the colors should be harmonious, so that one person will not dominate the scene. Dark clothing tends to minimize apparent body size, while light shades do the opposite. Long sleeves are best for adults and older children.
Finally, in terms of hair styling and make-up it is best not to schedule your session immediately following a haircut. A week later is usually best. Also, your portrait session is not a good time to try out a new hair style. Women’s make-up should be appropriate for the clothing and portrait style desired. Most photographers suggest subtle make-up on most all women and girls, except for the very young.