Deep primary colors- The best colors, beside black and white of course, to wear for your photos are deep primary colors, like royal or navy blue, deep red, and mustard yellow, not too bright but not too dull.
Stay away from greens- If you are having a photo shoot with an outside setting, you should probably stay away from green to avoid blending into the greenery like trees and grass around you.
Dress for the season- If it’s fall you should wear fall attire like hoodies and vests. It would look pretty silly for there to be a fall background with leaves that are changing colors and the people in the photo are all wearing shorts and sandals.
Coordinate- A lot of people have broken the tradition of the family portraits with everyone wearing the same shirt and pants. Now people just coordinate, you don’t all have to be wearing the same thing but you should have a theme color. If blue is the theme, everyone can just have a hint of blue in their outfit and everyone will get the idea.
Clothes that fit nicely- Baggy clothes and pictures don’t work well together. Unless you want to look the size that the clothes actually are, I would recommend clothes that fit to your actual size.