If by'zeroing' you mean getting a 'round on paper' BEFORE actually shooting what I do (specifically with a scope) is I first 'zero' the scope by ensuring the 'dials' are both set at their 'halfway' points.
I then set the rifle on my shooting bench solidly supported and remove the bolt, open the action etc. to be able to 'see' through the barrel.
I look through the barrel and 'sight in' on a clear, small target at maybe 75 yards or so. Once the object is clearly seen through the barrel I simply adjust the crosshairs to zero on the 'target' - and then I typically set the crosshairs approximately an inch below the target.
At this point I am ready to shoot for actual target zeroing in however this has never failed me and ALWAYS results in shots very close to the bullseye on the paper target and one time I had my FIRST round fired hit exactly 1" below the bull at 100 yards!
Yes, I know there are devices available for this, bore lasers and other things but this is 'free' and works well!
Here is a recent 'zeroing' of my NEF Handi - Rifle with a new scope and rings. Oh, no ammo nearby and in my shop so the 'beverage' was acceptable!
