-Don't use Extras: These add additional layers to EVE or Scatterer, all of which cause additional lag

-Don't use other optional mods: planetshine, distant object, waterfall, Parallax, realplume, TUFX, etc.

-Turn down in-game reflection settings: KSP's reflections are poorly optimized, and having these set to max will result in a HUGE preformance hit, instead, turn them off, or have them on lower settings

-Turn down Scatterer settings: in the Scatterer menu (ALT+F10) in spacecenter view, select a lower preset or mess with the custom settings

-Don't use Scatterer: Scatterer has a significant performance hit and Spectra has backup EVE atmospheres that will kick in when Scatterer is not installed