The goal of a portrait session is to focus on the face. When choosing an outfit you don’t want to pick something that will draw attention away from your face. Avoid selecting outfits that feature bright colors, loud patterns, busy prints, or logos. Denim in any color for pants and jackets works well. It’s classic, it’s informal and it comes in lots of great colors. For shirts black is a great color, so is white and different shades of basic colors such as red, green, blue along with maroon make great choices. My personal favorite color shirt for portrait sessions is brown, or navy blue. If you have a session that involves more than one person such as a family session or engagement session be sure to choose colors that complement each other. It’s not necessary to be matching, but keeping everyone dressed in similar styles looks great.
The most important thing is to be comfortable. Wear something you can easily move around in. If your daughter hates wearing dresses don’t make her wear one for her portraits, if your son hates wearing shoes don’t force them. Being relaxed, laid back, and having fun, will show more in your portraits than the finest of clothing!