It's easy to pick up and play Call of Duty: Black Ops 2, but mastering the game is a whole other story. Good players who've spent ample amount of time in the game study the ins and outs of each map, remaining entirely aware of their surroundings. It's necessary to study the possible entry-ways, and choke points if you wish to excel in the game.
YouAlwaysWin has put together a helpful video guide on how to perform offense on Turbine in Search and Destroy mode. In it, you can see as he takes into account the various routes surrounding the objective and how he uses claymores to serve as an early detection system for enemies. He notes that it's necessary to use random players (assuming you have no friends online) to tell you where enemies are approaching from—which you'll learn about when they die and disappear from your map.
In the video, he advises players not to rush and to stick to a strategy while on a map, and to always place a claymore at certain spots where enemies are sure to show up—regardless of whether they did so the last time.
Anyway, if you'd like some helpful advice on how to perform on Turbine, check out the video below.