If you mean sleeping the display and not the whole computer, I ended up defining a hot corner to do it in the Displays preference pane in System Preferences. Th

If you mean sleeping the display and not the whole computer, I ended up defining a hot corner to do it in the Displays preference pane in System Preferences. Then I can just swipe the mouse/trackpad to that corner without worrying about overshooting, works every time. I used to use the keyboard shortcut until I got a Mac without the power/eject keys.