You can find a lot in books and on the web about the quality of light. While good photography can be done in bright light and high sun the low sun in Spring and Autumn does give one more opportunities. Now we are in Autumn a walk in a local grave yard revealed a bit low sun catching the top of the angel sculpture. A simple shot made far better with the low directional sunlight.
This shot of a Tufted Duck would look dull without the low sun illuminated it from the front.
Its also a technique that can be taken into the studio with this shot above used as good example, a softbox close up from the side with a little fill from a top hair light.
One should consider light for its direction and its colour, when using flash the source size is also an major consideration.