With Nova Launcher, setting gestures i.e swipe down to expand notifications, or double tap to launch play store.
Setting a shortcut to directions to your house on your home screen. Then when you're out and about, one click and you've got turn by turn directions home.
Using the app "popup widget", and with Nova Launcher's swipe up to activate shortcut feature, you can swipe up on an icon and it will open that app's widget (or any widget for that matter) floating above your home screen. This is to replicate the same feature in Action Launcher.
Using "gmd gesture control", I have set it so that when I swipe up from the bottom of the screen, it will run "tiny apps", and voila, floating browser, calculator or notes - from anywhere!
If you password lock your phone, a combination of Widget Locker and PowerToggles can let you toggle some settings, such as turning up the volume or using the flashlight, without unlocking your phone
Home2 Shortcut can let you customize what double-tapping your home button does. Very helpful if you have a Samsung but don't want to use S voice. I set mine to go straight to Google voice search instead
On S3 or S4, a lot of those "gimmicky" gesture controls are actually pretty useful: turn on "double tap to top" for quick scrolling to the top of a list, "Direct call" for easy calling, and "Smart Stay", when it works, for fast notifications
In Google Search, go through Settings>Phone Search, and check everything you use. Let's you search through your phone or other apps straight from Google search. For example, you can search for a contact without going through the Dialler, find an app on your phone, or open a document without finding it in Drive