[AT&T Samsung Galaxy S 5] d34thbl00m:
Hello guys and gals! Been a while since I've started a thread heh. So let me start off by saying this thread is a collection of both tweaks I've found through my incessant tinkering and apps I've come across throughout the last few years. That being said the apps I will cover are the work of the developers who created them and all credit goes to them.

Settings Tweaks:

One of the first things I do on any Android phone is enable Developer Options under system settings (you do so by tapping build number under about phone 7 times). There is a specific group of settings in there that can help give you more screen on time with less battery drain.

Window animation scale, Transition animation scale, and Animation duration scale can all be turned off. Without having to draw these animations constantly your screen will consume less power, and may even seem snappier.

I know there are very mixed reviews of Smart Stay, but I feel like it can only help. Samsung has also included some settings to adapt the brightness and color based on the onscreen image in order to save battery. I assume that can only help our cause. Disabling the screen to wake on all buttons except power can also save wasted battery from your screen turning on in your pocket (there are xposed modules that can do this or you can get into editting key layouts with a root browser).

Lastly, as far as user level things for helping with more screen on and less power use, keeping your wallpaper on grayscale or dark images and using dark theming really helps as drawing light colors on the screen uses more energy.

Power Saving Tools:

The first on the list is a heavy hitter, the app Greenify. I cannot stress enough how crucial this app is. It allows you to put set apps into Hibernation, stopping them from running in the background and eating your memory and causing wakelocks preventing deep sleep. It has a great built in auto-hibernation option in settings which I highly recommend enabling.

I also suggest supporting the developer and buying the pro version. It enables some experimental features which backbone on the Xposed framework, allowing you to hibernate system apps, which proves very useful for running services that don't need to be 24/7.

Paired best with Greenify is any one of the large selection of battery monitoring apps. The best one in my opinion is GSam Battery Monitor, it gives you a detailed breakdown of what is using your battery so you can hone in on sources of drain. BetterBatteryStats and Wakelock Detector are a couple more of my favorites.

Tasker is quite possibly one of the best apps out there. Another one I highly suggest to support the developer and buy the pro version. You can set up automation tasks to control your phone without lifting a finger. In order to get the results we're trying for it will also need the plugin app Secure Settings.

I have 3 profiles that are relevant. The first 2 are linked, Home Mode and Away Mode. Home Mode sets all of the settings shown above in the At Home task when WiFi detects that it is near my home network. When WiFi detects it is NOT near my home network, the settings change to what is shown in the Away task image above. Allowing Tasker to control the aspects will help make sure your phone is more battery friendly when you are away from a power source.

The third profile is a simple Shake to Greenify, which hibernates all set apps through Greenify by a good shake of the phone.

Even though we cannot overclock due to the locked bootloader, don't forget about the option to underclock which can greatly save power. I use SetCPU to run 2 profiles, one which slows the CPU to a crawl when the screen is off preventing any apps from going too crazy with cpu wakelocks. The other profile gives the full range of voltages when the screen is on. I prefer to use OnDemand as my governor to save cpu power for when I need it.

Last on the list is Lux Auto Brightness. The free version does just fine; this app controls your light sensor far better than the native auto brightness setting, and the different update modes give you different options as to how you want the brightness adjustments handled.

With this list of tweaks and helpful app usage, I encourage you to test and try different things to find what works best for you. Hopefully I have helped in your quest for better battery life. Cheers!