Mac: Auto-restore works great when you want to pick up where you left off, but how many times do you leave open a photo or video you actually want to see again when you re-open Preview or Quicktime? A couple of terminal commands can disable this annoying -- and potentially embarrassing -- feature.
Enter this into Terminal to fix Preview:
defaults write com.apple.Preview NSQuitAlwaysKeepsWindows -bool fals
And this one for Quicktime:
defaults write com.apple.QuickTimePlayerX NSQuitAlwaysKeepsWindows -bool false
That's it! Just change false to true at the end of both statements to bring back auto-restore.