Do you use auto white balance, let the camera get the exposure, or use a colour checker and grey card. Meter your flash carefully with your flash meter, or just guess by eye.
All approaches are valid but having a system that gives you a consistent base is in my opinion is best, its certainly what works for me.
That saying, getting things technically correct is not the be all of a great picture. Having a consistent base to work from makes life easier when you want to get creative.
In the picture above, I have tweaked the colour balance, saturation and added colour grading to the shadows and the highlights. The resulting image is certainly not ‘correct’ in exposure, white balance or colour but I find it a pleasing image.