My clan and I are a straight Domination clan only.  We use this strategy which is pretty basic and I would guarantee others use it.
 
We start with 5-6 people and one person stays back and camps our home base flag. He never leaves and always hides with Ghost and uses a slinencer.
 The other team mates charge B but before we move in to capture it we all hide tactical insertions near it so we can still be near the fight even if we die.   
We NEVER I repeat NEVER go past B, because if you do the enemy begins to spawn at the home flag and our camper will be gunned down and we lose our home base and all hell breaks lose.
We also synchronize our killstreaks, three use spy plane and the other uses counter spy plane. Two will use sentry gun and two more will use SAM sites. The ones that don't use either of those put on napalm, B52, and blackbirds. The team leaders decide when to use the killstreaks so no one waste killstreaks. 
 
If we lose B one person will flank the enemy and take their homebase so they will scramble and try to take it back, or go after ours. During that we take B back and move into our original positions.
 
So would anyone have any idea how to improve it? 
We are going for a MLG team but not until we perfect our strategy and find more dedicated (try hards) teammates.

Purple penises on all guns.
 
Instant victory.

"You are what they refer to over on Gamebattles as Pub Stars.  

 You would be better off giving up on everything you just said, adopting the purple penises and running around aimlessly.

 Also also never use the term "Try Hard"   Kids have no idea what it originated from or what if even means anymore.  They sound so fucking stupid trying to use it. "

" Purple penises on all guns.  Instant victory. "

Capture flags that aren't yours and don't lose flags that are yours.