Do u guys take custom WB setting for each shoot?

Do you base your metering off of your backdrop or off of your model? Also when you shoot do you use spot metering, or dynamic, etc...?

I shoot in RAW, but my WB is always in flash mode in the studio

Every time i set up a shoot, or change things around, I base my WB on a new image of a WhiBal card under the same lighting.
I normally CWB, but keep the image anyway for future reference in PS.

I set mine with my Expodisk everytime.

Backdrop? Why not meter what's most important?
My 1-cent flash "meter" in images 5S & 6S.
Simple 2 Light Portrait Set-up

Shooting in RAW I never really bother setting custom WB as I know I can set it later in Lightroom so my cameras are set on AWB all the time.

Less custom WB - but more so a specific one. If I'm shooting a bunch in a series it's more important so that each photo looks similar and you don't end up with one being warm, another right on, yet another too cool, etc. AWB does a pretty good job for random shots, but it's the ones in a series where it pays off to be more precise/choosy. Saves time later in PP and ensures consistency. I shoot RAW so you have more leeway to adjust in PP if necessary.

Outdoors, it seems to be close. Not indoors, though. Notice that the very last exposure in the 2nd group of tests was of a gray card.
https://photography-on-the.net/forum/showthre​ad.php?t=54281

No, I used to consistently set for standard sunlight (5200k) but now use 5500k. So far, I like the look and since I shoot RAW, it can always be changed in PP.

Nope..I shoot jpeg (shot raw for 2 years, hate it) and I set my white balance to whatever situation I'm shooting..or since I use CS3 I can set my white balance to Auto and fix in the raw editor of CS3 the same as raw files.
When in a fast moving wedding or some other event, last thing I need to worry about is white balance setting as it moves from room to room or location to location.

I use AWB 100% of the time.
Outdoors, it does well.
When the lighting becomes questionable (typically indoor lighting) then I will use my WhiBal card, take a reference shot with it, then apply to the rest of the series during RAW conversion. Nice and simple.