Light is an essential factor in photography. Multiple strenuous attempts can be made on the same photo to get the lighting of a photograph just right. A bright environment alone does not necessarily create the perfect lighting conditions. The direction of the light and where it lands on the subject are essential considerations, especially in bright situations. Sometimes the light will need to be guided to certain areas, and to do this you need a reflector.
With outdoor portraits your subject’s whole face needs to be well lit and the light needs a balanced distribution. In bright sunshine, sharp shadows can be created, especially under the nose and chin. This can cause distortion in the photograph and can produce unflattering results, which the subject may not be pleased with at all. Bringing a reflector or, if you want to push the boat out, multiple reflectors, can light up these dark areas and provide a fuller picture.
The reflector need not be confined to the outdoors. Inside it can help reduce the necessity for the flash and accentuate the natural light in the room. Artificial light can also be guided around the subject, as the reflected light is often less harsh as the direct light. If your camera has the ability to move the flash, then reflectors can be used to bounce the flash light on to the subject.
“But how do I use the reflector?” I hear you asking. It is relatively simple, although you will still need to experiment and test to see which lighting is best or is the one you are looking for. Try and get the reflector as close as you can to the subject without getting it in the shot. If possible, try having the subject hold the reflector. Try and get the subject looking away from the direct light and position the reflector so the direct light is reflected into their face. Move the reflector around until the face is evenly and well lit. It may even help to have an assistant to move the reflector for you. Adding more reflectors will help get light all over the face.
Now, all you need to do is get a reflector and then you are ready to go out and take some well lit photographs. The cheapest method is to make one yourself. Tinfoil can act as a useful reflector. Try to use the less shiny side to avoid bright distracting reflections. Large light colored cards can also be used. The best option, however, is to buy one. There are two main colors: silver and gold. Silver gives brighter, whiter reflections whilst gold gives a warmer and subtler light. Reflectors also come in all shapes and sizes, depending on your uses. Many fold up into a small portable size to make it easier to carry. Amazon supplies a good range of reflectors.
*Image courtesy of www.geofflawrence.com 
As with everything in photography, practice makes perfect. Do not expect that since you have a reflector shining at your subject, their face will instantly be perfectly lit. Move the reflector around to get the shot you are looking for, or try experimenting to see the subtle effects and changes you can produce.
Here is a list of some good reflectors:
Adorama 42″ 5-in-1 Collapsible Disc Reflector
Paterson Interfit 42″ 5 In 1 Portable, Collapsable Reflector
Norman 42″ 5-in-1 Collapsible Disc Reflector
Adorama Collapsible Reflector Disc 32″ Portable Reflector
Adorama 32″ 5-in-1 Collapsible Disc Reflector
Lastolite 48″ 5 In 1 Bottle Top Reflector Kit
Photogenic Chameleon 22″ 5-in-1 Collapsible Disc Reflector