KOS Tips

Mini guide by synpase
Shooting
1. Whilst crouching, shoot a full clip of bullets into the wall (not too close, not too far away. From one end of the Training Camp spawn area to the other end is a good distance) without moving your crosshair, and watch the pattern of the bullets. When does the bullets start to rise? What is the average spread of the bullets?
After you feel you know the pattern well enough, crouch and shoot another full clip of bullets into the wall, but this time move your crosshair down to adjust for the recoil. As you become better at adjusting for recoil you will be able to spray at close-mid range enemies and still have a high percentage of hits.
Repeat this for standing, and then for moving (either forwards/backwards or from side to side)

2. Aiming for the head is also important if you're using assault rifles or the weaker snipers. If at close range, SMGs and shotguns should be aimed at the head as well. Otherwise, for inaccurate SMGs or shotguns at mid-range, or high-powered snipers at any range, aim for the upper chest.
To practise your aiming, find something to look at (a pot, a sign on the wall, anything). Move your crosshair away from the object, and then 'snap' to the object (aim quickly). Try not to take over half a second to aim; it doesn't matter if your aim is off, but you will need to learn to aim fast to survive. Repeat this at different distances until you are reasonably comfortable at snapping to a target.

3. Also practise aiming at an object whilst moving. Find an object again and strafe around it from side to side, making sure that you are keeping your crosshair over the object at all times. When you're reasonably comfortable with that, start shooting at the target. Remember what you learned before and pull your crosshair down to compensate for the recoil.

4. Finally, using everything that you've learnt before, move your crosshair away from an object, snap to it and start shooting whilst controlling your recoil. See how many hits you land on the object from first 'seeing' it and snapping onto it. You should manage to start landing hits within a second of seeing the object.

5. Substitute the object with an enemy's head and get fragging. Good luck! :)