The habit I've gotten into when trying to target enemies directly in front of me has been to zoom in my camera and play with a more "face down" instead of "face out" over-the-shoulder view. The tab targeting will not select anything you cannot see, in most circumstances (clipping and weird angles aside).

Then I have on my controller R3 click set to put my camera back to its "default" state -- which for me is the highest, widest field of view possible for maximum situational awareness. This way it takes me a second to zoom in for precise targeting, but only an instant to get back to the action.

The TRUE solution to my problem is just: Overpower, Overpower, Overpower....