same way when i am getting my photos done and i am a photographer for a living! so you are not alone in thinking this.
1. get dressed up! the more you get dressed up the better the photos turn out. don't be afraid to put on that fancy coat, cocktail dress, or new boots.
2. stay away from neon colors including red! camera's have a hard time with red and neon colors, they tend to get easily blown out in photos and have no detail or texture to your clothing. you don't want to look like you jumped in front of a green screen at a movie set!
3. patterns are great 