no scope technique:
1.drop shot, run up to some one and get prone as soon as you land on the ground shoot.
(make sure to have button layout as tactical)
2.crouch shot, crouch as soon as you shoot and the shot should be more acurate.
(make sure to have button layout as tactical)
3.old-fashion double-tap, pick a shotgun or machine pistol as your secondary then double tap (Y) and shoot
(no tactical button layout needed)
4.the side step...[NOT recomended]: when you n-scope just walk in a zigzag or step side to side and no scope

quick-scoping techniques:
1.sneak-peak: look down the site for less than a sec and release and shoot.
2.fix your cross hair to a corner and when they come running blast them