So, there are many tricks in random maps that can make make a massive difference in a multiplayer game. I'll list a few: You can drive a a hog up one of the mountains in bloodgulch, and you can also drive a tank up the same mountain, also, you can drive a ghost up the mountain boundaries. Also, in damnation, where the sniper rifle used to be but now 343i put a needler there,right below you, an overshield would spawn in the old Halo game, where, if need be , you can just down directly on the overshield and survive. Lastly, Danger Canyon, in the base thing in the middle on the ground, there are two ramps facing each other, and in the middle there is an overshield, which you can drop on top of from the bridges above. Also, you are able to drive a hog through the doorway in the actual base.
Those are some tricks that I noticed, and I hope they are there in the actual game.
Sorry if this had bad grammar.. I just put it together quickly.