Personally, a King of the Hill variation on Xbox Live is my second favorite game type, directly behind Slayer battles. The action is fast and furious throughout the entire game. I hate to give this tip away as it has allowed me to win almost every King of the Hill contest on the Warlock Map.
King Over the Hill Not many players seem to know this trick yet, but it is extraordinarily beneficial and easy. During Crazy King games on the Warlock Map, the Hill will move to the structures on the outside. The Hill will either move to the bottom of the structure or to the second story or roof. When the Hill is on the bottom, you can stand on the top and still earn King time! While everyone else is blowing each other up below, you can squat on the roof and earn an easy 20 or 30 seconds as King. This will almost guarantee a win. This is a great way to boost your player rank.
Bonus Tip! Don't worry if you are occasionally spotted and fired upon, just fire back and act dumb - as if you have no idea what you're doing. The opposing player will probably just hurl a grenade at you as he runs towards a quick death below.