While this may sound like a given, it's easy to underestimate how much of a performance improvement you can get just by updating your AMD or Nvidia graphics card drivers. You can do this through the AMD Catalyst Control Center or the Nvidia Control Panel, or by going to the companies' respective websites. Considering how simple the process is, the potential improvement to game performance from driver updates is nigh-on miraculous. Driver updates have been shown to boost performance by up to around 60%. Bear in mind that more recent cards are likely to reap the most benefits out of driver updates. It's still worth updating drivers for older cards too, but don't expect the results to be nearly as drastic.