Facial sprays seem pretty unnecessary if you have never tried one. However, a good facial spray can help tone, refresh, and moisturize the skin in a quick and very easy step.
I have been using Mario Badescu's Facial Spray with Aloe, Herbs and Rosewater ($12) to set my powder foundation if it is feeling a little cakey. It is also awesome as a refresher after being outside in the hot, humid weather. Plus it smells SO good!
On my clients, I have been using Caudalie's Beauty Elixir ($18) to tone and/or set makeup. This facial spray contains essential oils (herbal-smelling) which help boost radiance as well. The Beauty Elixir is formulated without synthetic fragrances and colors and contains no parabens, sulfates or any other junkie stuff.