you don't say what your loading so here's what I do:
Pistol and plinking rifle: Once I get it adjusted to throw the amount I want I then throw 10 loads into the scale cup and measure. If it's within .2 grains either way it's good to go. Example, I want to load 5 grains. 5X10=50 so anything between 49.8 - 50.2 and I'm happy.
Target Rifle: I set it a little low and trickle to finish. Every load is weighed.
Note: if your going to load "HOT" weigh every load!
around ten before starting, then check it every 50 rds or so. if your using a loading block scan the block when loaded you can usually detect any high or low loads by eyeballing