[1]My guess is that you are investigating this tutorial for the same reason I began to envelop myself into being a counter-sniper. If you are reading this for helpful tips on sniping others that are making a legitimate effort to win the match, then this is not an article for your despicable self.
[2]To begin, you need to understand whether you are actually needed to be a designated counter-sniper. It depends upon the situation. In general, if there are more than 9 or 10 people on the enemy side, then you might be needed to the call of arms. If there are 6 or less people on your team, do not even think about touching the recon kit because you will be a complete liability on the team. If the team meets the minimum of 9 people, then consider choosing your usual kit selection. After the first skirmish arises in the match, evaluate the frequency of sniper kills to see whether you will be facing two or three other snipers. Any less and you will become only a liability to the team yourself. Like the dilemma other snipers face, you need to ask yourself "Am I beneficial to the progress of my team?"
[3]If so, then ready up your recon selection with preferably a bolt-action sniper rifle that is not a Russian or Chinese manufactured design. The bolt-action rifles deal much more need damage and host greater accuracy. The Russian and Chinese manufactured rifles have a crosshair that uses an arrow to signify where the bullet will hit, but because the tip of the arrow is hard to pinpoint where it ends, it is difficult to make a pinpoint shot at great distances.
[4] The next step is to spot the enemy shooter, use the "back" button to place that little triangle over the enemy's head. If you spot multiple targets and do not know which one is a sniper, it is the target that is sitting still or moving slower than the others. Can't spot any snipers? Use the sniper's most useful tip; use your peripheral vision to spot movement on the screen. Look for moving globs, flying bullets, muzzle flashes, and listen for the origination of the bullets crackling sound.
[5]Now look for a sniping position that is not well thought of and think of a next spot to retreat to. Around the lining border of the map, a rarely used hilltop, bushes, windows, creaks, isolated rooftop, or even in the middle of a side street are good choices. The location should be one a sniper would last investigate when under fire and preferably far away enough that the spotting system deems unreliable. Understand that you should stay in that location only until you kill at most two snipers or have exhausted around 5 rounds (I would say you can double the time duration of sniping the enemy safely, if you position yourself somewhere where only the shoulders and head are only visible and you crouch in between shots). This will not only keep the sniper guessing, but it will save you from watching the dreaded "death cam." Do not be a "dumb" counter-sniper and eliminate the assault teams battling for victory. It will only cause them to revert to them unnecessarily targeting you!
[6]Now for the fun part, killing the sniper. Aiming the crosshair and shooting is not the full story of the game! There is now something called bullet trajectory that you must consider. Bullets act very similar to arrows when shot, they are tugged by gravity to hit the earth and have a delay time till they hit the target. Aim just slightly above the target's head to compensate gravity and aim ahead of where the target is moving. Use the "ambush" technique when neutralizing moving targets (the ambush technique is to set the crosshair far ahead of the target and waiting for the target to land just where you want them to kill them). If you are not sure of the distance or time delay of the shot, "range" a shot. Ranging a shot is to fire a bullet at a wall that is at similar distance from you as you are from the target and how long the bullet took to hit the wall and evaluating where the spray of debris is located on the crosshair. Use the ranged shot to adjust your aim. Remember, the farther the target's distance is, the more exaggerated these adjustments should be. The ideal distance from the target should not exceed -1 vertical mil dot on the crosshair (a mil is represented by everyone one of those little dashes or dots that spread outward on a line from the crosshair's center like on a ruler). Now understand that your manifest purpose is not to neutralize the target necessarily, but to limit the sniper's time firing upon your allies, so do not fret about making only a body shot. If the sniper ends up last on the leaderboard, then you completed your job miraculously!
[7]If you make a body shot and you are targeting a "dumb" sniper, wait for him to poke his head out to look where you are. If it is a "Now if this happens to you, being the "smart" sniper after reading this, you will never ever think about doing something so stupid! Remember, if a sniper bullet whistles by you or a mortar strike is called near your position, retreat to the secondary sniper position you thought of in the beginning. The only exception is when you are heavily engaged with that sniper and can take them out.
[8]Now with all of these critiques should most definitely peak performance. I do hope to the greatest intent that my tutorial is found helpful to you. Because this is a tutorial on the forums, let's try to get this stickied so others may see this, please!

Also please give comments for any improvement upon any future tutorials.