National Battery Day Tips and Tricks from HMD Global, The Home of Nokia Phones

Hold back on 100: Always charging your phone to 100% when using a high voltage charger can put strain on your phone’s battery. Pulling the plug at the 80-90% mark is a good idea, and you ideally always want to keep your phone’s battery between 30-80%. This will increase the lifespan of the battery.
Switch off your location: On Android phones, you can either switch off your location/GPS completely or block certain apps from tracking your location. See Settings > Apps in order to check what apps are using your location and switch these off. 
Avoid exposing your phone to extreme heat or cold: Extreme cold temperatures can drain your phone’s battery faster. Keeping your phone at room temperature where possible, will ensure the battery lasts as long as it can.
Charge your phone during the day: If you want to keep your phone’s battery healthy, charge it during the day and not overnight. When a phone is left plugged in, the battery will start to drain again. Once the charge level drops below a certain threshold set by the manufacturer, it will charge straight back up again. Ultimately, this can speed up the battery degradation, so you may end up finding that your phone ends up at 0% quicker than when you first bought it. If you do charge your phone at night, make sure it is not covered up e.g., under a pillow, as this can overheat the battery which will also worsen its performance over time.