Reduce transparency effects
System Preferences >> Accessibility >> Display >> Reduce transparency (On)
Switch off automatic graphic switching
System Preferences >> Energy Saver >> Automatic graphics switching (Off)
(Turn this back on if using battery power for long periods.)
Tune Mission Control
System Preferences >> Mission Control >>
Automatically rearrange Spaces based on most recent use (Off)
Displays have separate Spaces (Off)
Dashboard (Off)
Fix disk permissions, reset System Management Controller, reset PRAM
(Luis Mercado explained this well at https://discussions.apple.com/thread/6623697)
Sources:
http://osxdaily.com/2015/04/06/windowserver-high-cpu-usage-mac-os-x/
http://apple.stackexchange.com/questions/153397/windowserver-high-cpu-on-yosemite
Sources:
http://osxdaily.com/2015/04/06/windowserver-high-cpu-usage-mac-os-x/
http://apple.stackexchange.com/questions/153397/windowserver-high-cpu-on-yosemite