Play The Field
It's no secret that knowing is half the battle. When you step onto the field, make sure you know what you're getting into. Understanding the layouts of all the maps is crucial to finding the most useful weapons and strategic locations that can make or break an entire match. Be mindful of where you're going and where you can go in case things turn sour mid-firefight. The best way to get familiar with all 10 of the maps is to hop into Forge Mode and examine them in detail. Find the nooks and crannies that will be your salvation, and memorize them.
In addition, reading the battlefield is intensely important to avoid walking into danger zones as well as knowing where your opponents are most likely to hole up. Most often a choke point will be established early in the match somewhere between the two starting spawn locations and it often doesn't move. Know where this place is and you'll always know where to go to find yourself someone to kill.