I just pour until the customer is happy. Screw the liquor cost.
No, seriously, I practiced myself to DEATH getting my pour count as accurate
as I could (I still haven't bit the bullet and bought an Exacto-Pour, but I
eventually will, I know). Then, as SOON as I got consistent and accurate (to
a certain level - I still can't do 1/8 oz. pours), my boss tells me he wants
me pouring heavy. Ugh. Now, my standard pour is 1 3/4 oz. for a basic
highball. He asked for it, he gets it.
Slightly off topic, yeah, but I think Adam answered this question about as
fully as it can be answered.