Let's talk Nia Long. Gorgeous as she is, her glowing appearance from head to toe makes her look especially gorgeous.
Body lotions contain luminizers, gold flecks or a natural looking amount of shimmer help to enhance your skin tone and help to cover any imperfections as well. One that I personally use almost every day is Palmer's Cocoa Butter Lotion with Shimmer. It gives your body a healthy amount of shimmer and I definetly gets compliments when I have it on. If you don't mind paying a bit more money, people have been raving about ModelCo Shimmer Airbush Luminizer.
For a glowing face use a moisturiser or primer with luminizing properties that enhance your glow. Benefit's Moonbeam is a cheaper version of YSL Touche Eclat, and help to highlight your complexion. On the tops of your cheekbones, down your nose and a little above the cupid bow of your lips are the places to use these products.
Another cheap trick is Vaseline! Put it where you would any highlighter, down the nose, on top of your cheekbones etc. This trick is used at fashion shows as well.
For glowing hair use a shine spray/serum and make sure your hair is frizz-free. If you have frizz it makes it harder for the light to shine on the hair shaft and give it that beautiful sheen.
So get glowing & show the world how beautiful you are!