I would share some experiences and give you some advices to avoid difficult choices later:
1. Shoot RAW, correct WB in PP.
2. To have better insight in PP, before shooting use some grey card - anything from the above suggest list of accessories to get the WB reference
3. Don't change lightning between calibration and shooting because it will change your WB setting. If you use ambient light a little different than the main source, even changing ISO and shutter speed will influence your WB reference
3. Avoid shooting at lights having different temperature:
a) in rooms the tv can cast a strong lighting changing instantly - turn the tv off when shooting because no grey card will help you if the tv's light has an influence on subjects on the photo
b) if you have to use ordinary bulb lights and flash at the same time, try to get most lighting with the flash or the opposite way (avoid mixing different lights in similar proportions, unless you really know what you do). You can achieve this by setting the flash to ETTL and camera to low ISO, 1/200s casting the light from the ceiling (if white or natural grey)m- this makes more light from the flash than ambient. This will cause the flash to fire with more power and will override the ambient light from the bulbs having different temperature and making mess. You can first fire flash in manual mode with full power (M 1/1) to check what are its the capabilities in your current situation. The opposite situation - to get only some enlighting fom the flash will be achieved with opposite settings - high ISO, low shutter speed, ETTL mode. This you can check by setting (M/128) on your flash and setting all the other exposure parameters accordingly.
c) candles, tungsten, bulbs, flash are sources of difeerent temperature so will give you different WB settings. Try to avoid mixing them
d) some fluorescent bulbs blink with 50 or 60 Hz frequency. If you will shoot with shutter speeds above 1/30s you can be surprised how different your photos will be depending on which moment of the bulb's phase you have pressed the shutter
4. On your final photo try to find a natural WB reference - white or natural grey material which can serve as the WB reference. It helps often just to pick it.
5. When you do not control your light in most cases you will just have some kind of compromise...