Please see manufacturers instructions for specific information regarding the particular battery you have.
According to Popular Mechanics these actions can be taken to improve the lifetime of your battery.
1. Yes, you can leave your battery plugged in overnight.
It is not the end of the world if you don't unplug your battery the second that it is charged. That charger is smarter than you give it credit for. Leaving your battery on the charger all night (or all day) is far better for your battery than running it down and charging it up.
2. Charge a little bit whenever you can.
Lithium-ion batteries don't respond well to being charged all the way up and then run all the way down. They take much better to little bits of charge here and there.
3. Keep your batteries cool.
Speaking of temperature, make sure you don't leave your battery in a hot car all day. Or place it on top of your gaming PC. Or use it in a sauna. Also, beware of quick chargers. While your phone and charger are generally smart enough to minimize damage from high-voltage chargers, a lot of power super fast can generate extra heat. And if you have to store a gadget or its battery for a while, do it in a cool dry place.