There are a variety of set-ups and all are very effective. It is key to look into what perks best will benefit you along with your entire team.
Sleight of Hand: Standard perk widely used. Primarily cuts down reload time which saves you time, especially if you need to reload in the middle of a fight. On the other hand, it also serves the purpose of faster weapon swap time. With the right secondary you can drain your ammo clip and quickly swap to a secondary pistol to finish off enemies.
Blind Eye: Immunity to air support. Pointless when you have the Scrambler equipment. When positioned inside its radius computer controller AI will not target you.
Recon: Heavily underrated and underused. With proper technique you can paint an entire enemy team at the very start of a match with a Flash Grenade – this is a tremendous advantage when knowing where enemies head at the beginning of a match. The secondary effect will give you the same effect as explosives with bullets. Useful for when you can’t kill an enemy but you can fit in a single bullet. When combined with an A-UAV, Recon can have the same benefit as having an SR-71.
Scavenger: Scavenger allows you to pick up ammo packs from downed enemies, replenishing ammo for your primary and secondary weapons. Scavenger does not replenish Launcher ammo or Lethal ammo of any sort, except Throwing Knives. Scavenger is a valuable perk for builds using weapons with high fire rates, or builds that are stealthy or otherwise rely on a specific weapon, especially one with two attachments equipped. It’s also useful for play styles that are defensive or typically suffer a low number of deaths per round.
Quickdraw: Faster ADS time which is pivotal for winning gunfights against competent players. When combined with the Focus proficiency you can often defeat an opponent who pulled up their ADS first. It also offers faster equipment recovery which goes so overlooked. Faster equipment use is very useful when you’re stuck in a scenario and an overwhelming force is right around the corner.
Assassin: Immunity to UAV, C-UAV, A-UAV, EMP, and thermal vision. Extremely powerful perk and essentially negates a large majority of the Support strike package. Compliments a silencer very well. This perk also helps you flank under an enemy UAV.
Blast Shield: Useful for capturing points or holding them down. Objective points are often subjected to heavy explosive ordinance and therefore having Blast Shield allows you to survive longer on top of it. Works excellently with Riot Shield.
Hardline: Controversial. Useful for fast Support build-up especially with assists happening so frequently in many scenarios. However lacks the power of Quickdraw or Assassin. Works very well with Recon for gaining assists when you obtain the Pro version. An idea with Hardline is to use it to start your Specialist streak so you obtain your first perk after one kill.
Overkill: Overkill allows you to carry a second primary weapon. Overkill can be very useful for running two weapons of differing rand bands – typically an AR, LMG, or Sniper Rifle paired with a Shotgun. The AR/Shotgun build is especially dangerous on maps with mixed urban terrain. You can clean up in close quarters with a shotgun while retaining effective mid-range fighting power.
Marksman: Allows you to see enemy red names from a longer distance. Defeated by Assassin Pro. However, many people don’t use Assassin and you’ll have the ability to scope out enemies simply by pulling up your crosshair. Very useful especially when enemies are far and it is difficult to discern if they are scenery or a player.
Steady Aim: Useful for SMGs and SGs to allow for more strafing and hipfiring.
Stalker: Allows you to do the job of strafe firing while in ADS. The Pro version lags the trigger of player-position triggered equipment and killstreaks (Claymore, Bouncing Betty, I.M.S.) allowing you to actually run past it without it killing you.
SitRep: Will allow you to detect enemy ordinance through walls. Also allows you to identify booby trapped care packages. The Pro version magnifies the amplitude of enemy footsteps allowing one with a gaming headset to easily sound out enemies. In objective modes only the first effect really matters.
Dead Silence: Dead Silence is another powerful stealth perk. It grants you silent movement and the slight bonus of halving the period in which Recon makes you visible on radar (down to sis seconds from the normal 12). Dead Silence is most effective on offensive builds that use silenced weapons and Assassin to stay completely off the radar and nearly undetectable outside direct visual contact.
Choose perks that compliment your playstyle. If you’re an aggressive rusher with an AR, stick with the classic Sleight of Hand/Quickdraw/Stalker. If you’re an aggressive rusher with an SMG, you can dispatch the enemy team with Assassin and Steady Aim while still helping your team with Recon. If you want to really support your team, you can run Recon/Blast Shield/SitRep. There is no such thing as a perfect combinations of perks. I can’t tell you what to use and what not to use - you need to learn for yourself which perks are best tailored to your play style.
Video rundown of the different perks
Pro Perks
Sleight of Hand Pro: The Pro upgrade doubles weapon switch times, allowing you to swap to a fast-raising secondary at lightning speed. This upgrade also combos extremely will with either the Overkill perk, or simply picking up a second primary weapon on the battlefield that complements your current main weapon. An Assault Rifle and Shotgun combo works quite nicely.
Blind Eye Pro: Blind Eye Pro gives you powerful anti-air upgrades. It grants a 60-percent damage bonus to your shots, as well as armor piercing, which is necessary for damaging the heavy attack helicopters with bullets. On top of that effect, it also speeds up lock-ons with the Javelin and Stinger, exposing you to less danger when you shoot down air support. Note that the bullet damage increase is a risky upgrade, because firing wildly into the air is a great way to get shot. However, it does allow you to destroy all UAVs easily with an AR, and you can down helicopters extremely quickly with an LMG.
Recon Pro: Recon Pro upgrades this effect to include your bullets. This can be particularly effective when you use the Impact proficiency or an LMG and deliberately target enemies through walls (especially easy near objectives). Beyond the powerful benefits of knowing how an enemy is covering a room, highlighting enemies through a wall also opens them up to easy elimination with further shots through the wall.
Scavenger Pro: The Pro upgrade grants you two extra magazines on your starting loadout, which isn’t an extremely useful upgrade. However, it does give you ore leeway to expend ammunition before you have to search out packs, which can expose you to danger. Standard and Pro are also useful for builds running Impact on ARs or LMGs with the intention to deliberately dump ammunition through hard cover and into buildings. This is noticeably more effective in concert with a teammate running Recon.
Quickdraw Pro: The Pro upgrade is also very helpful, speeding up all Equipment usage by 50 percent. This means faster recovery from thrown grenades, and quicker Equipment deployment, which leaves you vulnerable for a shorter duration.
Assassin Pro: The Pro upgrade grants you immunity to CUAV and EMP effects – both the EMP Pointstreak and EMP Grenades. Even more powerful, it removes the red name and crosshair popup when an enemy aims at you. Assassin Pro is a near-mandatory perk for aggressive, stealthy builds. It’s also very important in deathmatch modes where hiding from UAVs and CUAVs can earn you a lot of extra kills. The temporary confusion that the absence of a name or crosshair alert causes an added benefit. Note that Assassin Pro renders you immune to the effect of EMPs, but it does not save your active Pointstreaks from instant destruction by EMPs.
Blast Shield Pro: The Pro upgrade halves the duration and effect of Flashbangs and Concussion grenades. This is another powerful effect for defending an objective or protecting yourself from an assault when you’re camping in a room.
Hardline Pro: The Pro upgrade allows two assists to count as a kill toward a pointstreak. It also reduces by one the deaths needed to trigger a Death Streak. The Pro upgrade is simply an added bonus. It helps take the edge off if you’re one of those players who has a chronic problem with kill stealers. Don’t bother with Hardline on a Specialist package. While it’s nice to get your perks rolling after one kill, there are better initial choices than Hardline.
Overkill Pro:The Pro upgrade allows you to take a single attachment for your second primary. Taking Overkill on your Specialist Strike Package build is very powerful. Overkill is the only perk that has no effect when activated by a full 9 Pointstreak as a Specialist. More critically, having two primary weapons gives you even more power when you unlock all Proficiencies.
Marksman Pro: The Pro upgrade doubles held breath duration. This is mostly relevant to newer Snipers and has a minimal impact on the Breath proficiency.
Steady Aim Pro: Steady Aim Pro causes your knife lunges to recover 40 percent faster, which can save your life if you knife one enemy when a second is nearby. Steady Aim Pro with a Tactical Knife Pistol or a Melee-upgraded Shotgun or Riot Shield is also quite effective.
Stalker Pro: The Pro upgrade is a nice added bonus: it delays the activation of Claymores, Bouncing Betties, and the I.M.S. The delay is long enough for you to sprint out of range easily – very nice if you happen to pass through a doorway while ADS and trip a Claymore.
SitRep Pro: The Pro upgrade increases the volume of enemy footsteps significantly. This is a very powerful upgrade if your audio system is up to par. With Sitrep Pro, it’s nearly impossible for anyone to sneak up on you without Dead Silence. It also allows you to pinpoint nearby enemy positions with greater accuracy.
Dead Silence Pro: Dead Silence Pro adds the strange bonus of eliminating falling damage. This is useful primarily for granting you new ways to move through levels safely. It can let you survive otherwise fatal or heavily damaging jumps and escape angry pursuers with ease.