1. Keep in mind that a good sniper doesn't necessarily get a lot of headshots. You can be useful without killing most of the time. In a team game, putting body shots on several opponents is extremely helpful if there are teamates around to clean them up. Sometimes sitting back and going for the easy hit will be more than enough to give your teammates the edge they need. Just don't stay too far out of the action and make your team play a man down.
2. Know the different types of sniping:
A quick-scope is when you zoom in quickly and fire right away, almost like you are shooting first, then aiming. While you're doing this, make a minor adjustment while you’re zoomed in to ensure a hit. A quick-scope is typically done from close to medium range, so the zoom makes the enemy's body (preferably their head) the predominant object in your vision, making it easier to readjust aim for a hit. Quick-scoping can be done extremely quickly, such as if you see an enemy jumping from above to a floor below. I you practice this often, your reaction time will increase greatly, improving you in all aspects.
No-Scoping.A no-scope is when you register a kill with the sniper rifle without zooming. In Halo 3 no-scoping has been made easier because, if the enemy is close enough, the aiming reticle will become red, indicating a hit will be registered. In previous Halo games, the sniper would only become red if it was zoomed. Use this to your advantage when no-scoping by consciously firing when the reticle goes red. Like other techniques, a no-scope requires a bit of luck and a lot of practice, especially at longer ranges. Remember that from close range you can hit once with a sniper rifle in the body and then melee, getting an easy kill. Going into custom games and practicing no-scopes will improve how you line up shots without having to zoom.
3. Positioning
The Sniper Rifle can shoot much farther than any other weapon in the game. For this reason, the way in which you position yourself on a map when in possession of the sniper is crucial to winning. While there’s no sure-fire way to get you 10 straight head shots or line up an easy triple snipe, if you learn to position yourself in the right spots you’ll become a much more effective teammate. * Stay back from, but not out of, the action. Don’t abandon teammates just because you found a sniper rifle. Registering a shot every 35 seconds will essentially force your teammates to play three-on-four Halo. Strong snipers place themselves based on the positions of their teammates and enemies, ensuring they get to fire on the enemy early and often.
* Use those objectives. In objective games you know the enemy has to go to it, so use this knowledge to your advantage. Position yourself far enough away to keep yourself out of immediate danger and fire away on the enemies as they move to take possession of and control the area surrounding the objective.
* Don’t get lazy. Opposing teams will target you once they know your position. Remember to check your back whenever you have a sniper, use information from your teammates and move around the map. Sometimes you’ll have to take out your battle rifle and win a close-range battle. Don’t try to get a crazy no-scope if the battle rifle ensures a much higher percentage of winning a battle. A smart sniper will actively move around the map and utilize their secondary weapon whenever necessary.
Learning the maps, enemy spawns and practicing with the sniper rifle will gradually give you a mastery of positioning. Watch this video of Neighbor using all of the above tips and doing a great job of controlling the pace of the game on Narrows by spawn sniping: http://www.youtube.com/watch?v=ksuvtoOD5lA&feature=channel_page
* Use those objectives. In objective games you know the enemy has to go to it, so use this knowledge to your advantage. Position yourself far enough away to keep yourself out of immediate danger and fire away on the enemies as they move to take possession of and control the area surrounding the objective.
* Don’t get lazy. Opposing teams will target you once they know your position. Remember to check your back whenever you have a sniper, use information from your teammates and move around the map. Sometimes you’ll have to take out your battle rifle and win a close-range battle. Don’t try to get a crazy no-scope if the battle rifle ensures a much higher percentage of winning a battle. A smart sniper will actively move around the map and utilize their secondary weapon whenever necessary.
Learning the maps, enemy spawns and practicing with the sniper rifle will gradually give you a mastery of positioning. Watch this video of Neighbor using all of the above tips and doing a great job of controlling the pace of the game on Narrows by spawn sniping: http://www.youtube.com/watch?v=ksuvtoOD5lA&feature=channel_page