You need to know the layout of the map in order to make best use of the space. If you get lost or stuck in a dead end area then you can kiss your life goodbye. Stick close to your team mates at all times.
You also need to learn the position of useful pick ups. There are weapons, health kits and various explosives in every map and they always spawn in exactly the same place. If you get familiar with the map you’ll have a much better chance of surviving.