Though it only takes one person to fire a sniper rifle, it really takes two soldiers to get the most out of the sniper-rifle weapon system. That's why snipers always work in pairs.
A sniper team consists of a sniper and a spotter. The two-man team offers many advantages over the deployment of a lone sniper in the field. The spotter carries his own special scope that is much more powerful than the scope on a sniper rifle. The spotter uses his scope to help the sniper observe objectives and set up the shot. The two soldiers work together to get to the objective safely and discreetly and then set up a position. Here's the general process:
• The sniper team uses maps or photographs to determine the best route to the objective.
• They walk or "stalk" (more on this later) from the drop-off point to the objective.
• They set up a position.
• They verify that the position is well camouflaged.
• They establish an escape route and a second, well-camouflaged fallback position in the event they are separated.
• They locate the target (or know it's on its way).
• They get into position. The sniper takes a spot on the ground that offers him the best field of fire. The spotter lies on the ground next to and slightly behind the sniper. He places his spotter scope so that it is as close to looking down the rifle barrel as possible.
• They work together to range the target, read the wind, and angle and adjust for other variables that may affect the shot.
• They wait for the target.
And in the words of Army Ranger Sniper, "Then you just take your shot and get the hell out of there."
(By Robert Valdes, How Military Snipers Work)