First of all I document the date, load, firearm & scope I use to zero along with ambient temperature & wind speed. I start out at 50 yards & get on target. I then move to 100 yards & shoot for groups anywhere on the target...if the group is acceptable I then shoot groups for center target. If my desired zero is 200 yards, and depending upon the cartridge, I shoot for groups at 100 yards above the center target where I estimate the bullet will strike center target at 200 yards. I then move the target to 200 yards and complete what I call a confirmation zero & complete any adjustments for acceptable center target groups. I do the same process at 100 yards for a 300 yard zero. I then pray to the shooting gods that I don't bump the scope way out of zero. NOTE: 1.) If you do not get acceptable groupings (second try) during the 100 yard zero activity it has been my experience that it doesn't pay to continue to zero with that load, because there are too many variables: rifle doesn't like the load/scope wasn't mounted correctly if a new scope, or scope was damaged/shooter was having a bad day, etc.; you need to step back and try a different load/remount the scope and/or check for damage/quit hard partying the night before you zero that firearm. 2.) If you are also using a chronograph during the zero process you can determine your desired point blank range parameters, because you have the zero point range, velocity, caliber & bullet weight..it helps to have that bullet BC, but not completely necessary.