In my quest for a batch workflow to produce proofs, I’ve found having a measured WB in the metadata really helps to get a better-looking proof. My cameras support collecting such a measurement and inserting it in the metadata of subsequent shots, and I’m finding this really works well in indoors-natural-light situations. I still just let the camera do daylight auto WB for grab-n-go exterior shooting.
Either way, I take a look at the proof and decide if WB needs further attention. And, what I usually do for that is to inspect the histogram, looking for shifts in the RGB channels, especially at the high end. Then, if I see a discernable shift, I just scooch the camera multipliers to line things up, and that usually makes the picture look better. Very unscientific, but it works…