I have always found that sighting in the right/left adjust first is easiest. Once you have your scope centered then you can work on your elevation (up/down). This may take a little longer but in the long run it I believe that it is worth your while. Make sure you take your time and let your barrel cool down between groups for a hot barrel will affect the bullet flight. Once you have the cross hairs centered then start working your elevation at about 20-30 yards. Make sure you are aware of the ballistics for your specific fire arm. Move back slowly to the desired distance and make your final adjustments. If you are using the firearm for hunting then try to zero in your score to the distance you most likely be hunting at. If you know your rifle's ballistics then you can always adjust in the field for that perfect shot. I have my 7mm mag zeroed at 200 yards. Even though the ballistics for this gun are fairly flat, by knowing the ballistics I know where to put the cross hairs of the scope for that 100-400 yard perfect shot. Use a gun rest when sighting in and once you are comfortable with the shots your gun is producing, then practise while in hunting positions and at varying distances. With a zeroed in scope and lots of practise you will become very confident with both your gun as well as your abilities to make that perfect shot.