Well with GMD Gesture Control I get quicker access to the things I need using custom gestures that are applied either anywhere on the screen or from select trigger points along the various edges of the screen. Some examples of what I set up include a thumb swipe in/out from the right edge executes the BACK command rather than using the back button. A 4-finger pinch goes home, tapping the screen with 3 fingers launches Textra (SMS app), tap and hold 3 launches Play Music, tap and hold 4 fingers does an ALT-TAB, a 5-finger pinch kills the current application, a straight swipe up from the bottom edge of the screen launches Google Now but swipes at angles from the bottom edge of screen will control previous/next tracks when listening to music. A 2-finger swipe up from the bottom edge gets me my equalizer (Viper4AndroidFX). All of these kinds of things are launchable from within any application and I've set them up on both my tablet and my phone so they have become second nature to me. The possibilities are endless as to what gestures launch what application/function.
With Tasker I'm working on making my phone more self aware by having it do things at set times or based upon set conditions. For example my phone not only reduces its volume settings when I go to bed but before I wake up it reboots and resets volume settings so that each day I start with my phone set up the same way. When I get in my car and the phone senses the bluetooth connection of my car it will know that I'm driving and act accordingly such as reading all SMS messages out loud to me. Its also possible to have the phone auto-reply to SMS messages to let people know that you're driving and will respond later. Since my car's bluetooth doesnt support media playback through the stereo I need to use an aux cable through the headphone jack so with tasker I have a profile setup that will set media volume to max when I'm in the car and the headphone jack is used. The phone will launch Play Music for me when it senses that I've plugged in the aux cable in the car. Since I use bluetooth all of the time I have a macro set to audibly notify me with a set tone when a device connects to it (just for peace of mind security wise).
Other root functions that I really need include using Titanium Backup to back up applications and data. I save 2 copies on external SD card so that if an update to an application is buggy or changes features I can roll back to a prior version. I also use Titanium to freeze applications that I don't use (a lot of Samsung apps that I don't like LOL).
Then there's Xposed modules . . . there's a module to allow you to set a custom gallery app that's launched from the gallery icon in the default camera app which is SOOOO helpful to eliminate the dreaded lag time between taking photos and viewing them. I also run modules to control what apps load at boot to reduce background processes that I don't need.
There's also Adaway which I sideload after root to drastically cut down on popup ads in apps and websites.
Tons of stuff . . . I'm sure I'm missing a lot.