If you need to get more battery life out of your Samsung Galaxy S6 here are the steps I followed that seem to help.
In Greenify set it to automatically close all apps that you reasonably can. These are apps that you don’t need running in the background, but that you can open anytime you want if needed.
Next set Greenify to aggressive Doze. Go to the three dot menu, then Settings and choose “Aggressive Doze (experimental)” and enable it. Greenify has a few setup steps that give it permission to do thing on your behalf, just follow those steps for it to work.
In Package Disabler Pro hit the check mark next to apps that you really just don’t need. These can include a lot of the bloat that your cell provider ships like AT&T Navigator, TuneIn Radio or others that you simply never want to use. Note that when an app is disabled the icon is gone and it no longer updates.
Next change the color scheme for the display. Go to Settings, Device and Display (this might be different for each carrier). Set “Screen mode” to basic.
Now install a black theme. This will reduce the power used by the display. I use the Material Black theme. This can be found in Settings, Personal, Themes. Then search for Material Black. It’s worth every penny.
Finally, make sure you turn off any features in Settings that you simply don’t use like Smart Stay, etc. These features are nice but if you don’t like or use them turn them off. This includes enhanced call features over LTE.
If you know you want be near a charger you can also set Power Saving mode which will under clock the CPU and reduce the screen brightness.