Sorry If you already Knew But Just wanted to help if you have any tips post

Teir 1
Sleight of Hand-120 kills(Domination or Demolition)
Recon- Go arond and stun people
Blind Eye - Go to Ground War and Shoot down killstreaks
Scavenger - Go play anything with unlimited lives
Extreme Conditioning - Any Game Mode Perferablly Dom or Demo and Keep Running and Gunning to have gun

Tier 2
Quickdraw- Have UAV then when they pop out aim down and shoot.
Blast Shield- Go to ground war because explosives and stuns count as explosives
Assassian- Ground War or Domination and Just get Kill during UAV/Emp/Advanced UAV
Hardline - Have Specialist Killstreaks and you can get like 30 points towards hardline
Overkill - Have your favorite Gun and put it as your secondary and Get kills

Tier 3
Marksman- Hardscope People with Barret for more one sot kills
Stalker - Aim down sights and get bunch of kills
Steady Aim - No scope wit FMG9 akimbos
Sitrep - Put trophy system on and Knife it counts as enemy equipment
DeadSilence - Run around with a soutgun(Striker,Model) Requires close range battle