When I first starting flirting with manual camera settings I was very intimidated by setting the custom white balance on my camera. Not sure why, it just seemed daunting. The truth was anything but. Turns out that you just take a photo with a grey card or cloth (I like the Spudz cloths) filling most of the frame and then browse through your menu until you find the "custom white balance" menu - my Canon has it on camera menu 2 - and then select the photo of the grey cloth (in the light you plan to shoot in of course) and that's it. You're done.
You may say to yourself, I am shooting in raw, I'll just fix it in post. You can do that, but isn't it easier to just do it right the first time? Or you're a JPEG shooter and you just put it on auto and shoot. Auto does a good job most of the time, but I have found that it never really nails it as well as the custom setting does. I put together a little montage to illustrate just how much of a difference the white balance setting can make. Below you see - from top left to bottom right - Auto, Daylight (5200K), Shade (7000K), Cloudy (6000K), Tungsten (3200K), White Fluorescent (4000K), Flash, and Custom white balance. As you can see, it does really make a difference. While the light temperature in my house is close to Tungsten, it is not a perfect match.
White balance is measured in Kelvin degrees and just like regular temps, the higher the number the warmer it is. It makes no sense to me that they do not order them by temp in the camera menu, but I don't design cameras so...
Anyway, food for thought. Have a good Wednesday!