a- don't do 100% discharges
Doing a 100% discharge can actually cause a failure.
See: How Lithium-ion Batteries Work
If you completely discharge a lithium-ion battery, it is ruined.
There is still the issue of how you use the laptop. If you drain the battery every day and recharge at night the
300-500 full charge cycle life span is a worst case scenario.
Lithium-ion batteries age. They only last two to three years, even if they are sitting on a shelf unused. So do not "avoid using" the battery with the thought that the battery pack will last five years. It won't. Also, if you are buying a new battery pack, you want to make sure it really is new. If it has been sitting on a shelf in the store for a year, it won't last very long. Manufacturing dates are important