Use a solid-color background. Professional photo shoots do not have furniture or props on the wall. Unless you are setting up an avant garde shoot, stick with a professional background. White works very well to bring out the color in a model's face.
Bring small props for optional use. If the photo shoot is for a musician, a small radio or toy instrument could be a fun addition.
Take pictures with multiple outfits. Ideally, you want to showcase three separate outfits. In post-processing you can choose your favorite outfit.
Use a quality camera with an SLR lens.
Always shoot in natural light. Outdoor light is the best, but if you are working indoors, always use light-diffusion techniques. A cheap way to diffuse light is with the Ikea Regolit Pendant Lamp Shade. These globes are used by many independent filmmakers to properly light actors' faces. If you cannot purchase the lamp shade, try and take indoor pictures by large windows.