My bedroom windows are covered with additional think comforters in pretty colors and are never open.
During depressing times or paranoid times my other Windows, the blinds are always down and firmly closed. Although I have no neighbors facing me I shut the blinds before twighlight so no one can see in. The blinds also have a sheer covering that makes it hard to see in. There's trees in front of the Windows too, so between the trees and the sheers it's pretty unlikely that anyone can see it....but still