These settings will get you the best visuals for the cheapest cost. Turning the settings higher does not significantly improve the visual quality but it WILL significantly increase the performance cost. If you have a weaker GPU you may want to set things lower.
- Terrain scatter: off (assuming you have parallax)
- Reflection refresh: If you have Deferred or Textures Unlimited, set to Low. Otherwise Off.
- Reflection resolution: 256
- Antialiasing: off (use scatterer or TUFX antialiasing; stock AA is incompatible with HDR + Bloom anyway)