Debloated ROM, freeze or delete apps that waste away at the battery, use auto brightness. Look for apps that wake excessively. Have you tried L Speed Mod? It will make Google Services behave. I use that with default settings, dump third party apps' cache and browser cache (including Google Play and Google Play Services) every 12 hours on a schedule and use an app by chain fire called recently to keep apps from running so much unneeded. Watch for rogue or faulty apps in the Xposed error log. Source close browser and other apps that like to keep running with back to kill app and use an ad blocker.