One of the most important things a photographer needs to learn to understand is lighting. Without it, it's essentially not possible to do any kind of conventional photography. Learning how to use different kinds of light sources is also important. Although natural light can be great, being able to use flash effectively is extremely useful.
One of the major benefits of shooting with flash is the increased control you have over light. Natural light can change quite dramatically at times, and this can put you at quite a disadvantage. It's not always convenient to have to wait for the "perfect light." If you're shooting professionally, chances are you have a schedule to keep to, and not all clients are going to stick around for available light to improve.
In a recent video from Westcott Lighting, photographer Ashley Boring demonstrates how you can use flash lighting to mimic any time of the day. From midday to blue hour, Boring runs through a number of techniques you can use, regardless of the time of the day it actually is.
My personal favorite was how Boring achieved the blue hour look. It's useful to see how she balanced the in-camera color temperature and the color of the flash in order to produce the look. This level of control is difficult if not impossible if you're just shooting with natural light. For that reason, if you haven't already, I highly recommend you take a dive into the world of flash photography.
Check out the full video linked above to see how Boring produces the different looks.