Counterstrike Source Tips: Know how to aim. As mentioned earlier, you should play with the mouse sensitivity that you are used to at all times. Know how far the crosshair moves when you move the mouse a certain distance. That way, when you see an enemy, you will know how far to move your mouse to put the crosshair on the enemy. Always aim for the head at all times, especially if the enemy is far away. Depending on range, certain guns like the ak47 and desert eagle are instant headshots even with a helmet. Without a helmet most guns will be a one hit kill headshot. However, for very close range combat, spraying and praying (holding down the fire key and randomly firing in the general direction of the enemy) can do the trick, but is mostly based on luck. Crouching and standing still while shooting are the most accurate, while moving and jumping while shooting are the least accurate.