Lower resolution
Use fullscreen mode
Set resolution scale lower
Reduce view distance
Reduce shadows
Reduce post-processing
Reduce anti-aliasing
Reduce textures
Reduce effects
Reduce foliage and grass
Disable motion blur
Disable ambient occlusion
Disable bloom
Disable light shafts
Turn off V-Sync
Cap FPS if needed
Close background apps
Update GPU drivers
Enable game mode
Use performance power plan
Overclock GPU if safe
Overclock CPU if safe
Install the game on SSD
Verify game files
Reduce server population
Avoid heavy mods
Restart the game regularly
Clean dust from PC
Improve cooling
Upgrade RAM
Upgrade GPU
Upgrade CPU