I shoot video more than stills for a living, being a DP. When using Canon DSLRs for shooting, white balance is set manually. But not the manual "shoot a white board", but set it in Kelvins. You can see what you are doing on screen as soon as you change 100 degrees. It is more precise and a lot quicker than shooting and then going into the menu.
If you are new to the concept of white balance, doing so will help you learn what you are changing. Tungsten light (the orangy light bulbs being now replaced for CFL except for movie industry lights) are in theory 3200, but to set the camera to actually see it neutral white, you'll find out that sometimes its more on the 2800 side. That is because for the lights to be 3200, the electricity has to be spot on the voltage, and it never is. It also depends on how much life the bulb has left. If its about to die, it will be less intense, and a bit more orange as well.
Daylight is 5600 but no always, sunrise, sunset, cloudy, VERY cloudy, and a lot of different weathers have different color temperatures.
Again, play with your settings on live view and you will learn a lot. You'll probably pick up on the fact that if your WB is higher than it should, then everything will turn more bluish. And if it is lower, more yellow/orange.
Some people use it to fake weathers (sunsets) and create moods in the picture. I stopped doing it after I realized it also changed all the whites dramatically, and sometimes that doesn't look good.
Hope it helps!