This is How you Boost and Lock a Lobby.

Free for All:
Need Someone with a Bad Connection
Remember to Put a Tactical Insertion, so you don't Forget
Get at Least 4 People in the Same party if they wanna Boost,
Get the Person that has the Bad Connection to Start a FFA and invite the Party to Game,
( Have to join the Session Kind of Fast )
Once everyone gets in then Everyone thats in the Game Votes the Map,
If you did it Right and Know one Joins you did it Correctly.

If thats too Hard for you and You just want to do it the Easy way, but cannot BOOST Kill Streaks then this one is Good for you.

( Make sure if your Boosting, put on Tactical insertion )
Bare Bones:
Start up a Party and invite all your Friends or the ones that are Boosting,
then Start up Bare Bones and Everyone has to hold X or Square until you get to your Custom Classes.
There you go.

This is SUPER DUPER OLD but just wanted to Post it for Fun.
Hoped i Helped,
Thank the Topic,
Rep ( Optional, you don't have to )

-NewinHD