First things first TURN OFF THEATER RECORDING.
Going to the main menu options, scroll down and disable theater recording for your profile and if you have a guest, that profile.

Most These Methods Are For Team Tactical But Can Be Done in normal game modes with more people!

THIS IS NOT PROVEN TO BE A SURE WAY YOU WILL NOT BE BANNED, JUST SLIMS YOUR CHANCES.
1. EVERYONE boosting ( GUESTS ALSO ) Turn Off Theater Recording.
Menu>Options>Disable Theater Recording. Do the Same for any guest controllers.
2. Don't Boost over 2000 IN GAME SCORE.
3. Don't Get Every kill a headshot. Looks suspicious when your last 300 kills were All headshots.
4. Try and Play Legit until around level 40.
5. I don't recommend boosting past 6th prestige until you have 2-3 days played. Alot of the time in pubs people will report high levels.
6. Take a break from boosting sometimes, let your leaderboard rank go down a bit.
7. Appear Offline
Will update.

How to Strafe Run Boost: Difficulty: Medium. XP: 50k-200k
You'll need
4 People(Including You)
2 Controllers

Stinger
Blind Eye
Hardline
Sentry Gun
Strafe Run
Assault Drone

1.You and 1 more person get in a lobby with your guests signed in, Search for a team tac
until it's SnD.
2.Invite the other 2 players with their guests signed in.
3.Pick One person from each team to go for that game. Everyone and Their Guests Spawn In.
4.Go kill the people in spawn then go to a bomb site. One person Plants The Other Diffuses.
5. WHEN you get killstreaks(sentry,strafe,assault drone) Call then in and let the other person destroy them for points.
6. To Destroy A Strafe run, use a stinger and shoot the VERY Left one. Now there should only be 2 beside each other, Shoot either one. Or if there's three side by side, shoot the middle.

That's Basically It. Just SnD Boosting While destroying Strafes, Sentrys, And Assault Drones!

Message my gamertag: Trohjan