Every deep discharge cycle of a li-ion battery will add up to reduce its life. So run the battery down to 0% as seldom as possible.
Shallow discharge cycles also reduce longevity a tiny bit, but more than proportionally much less than deep cycles. So keep the discharge shallow if possible.
Storage life of the battery is actually longest when partially charged. But if you are actually going to use your device as a mobile device, keeping the charge level nearly 100% will reduce the depth of any discharge plus full recharge cycles, and thus help maximize battery longevity. The smart charging circuitry will do this automatically if you leave it plugged in forever.
The recommended monthly full 100% discharge/charge cycles do nothing good for the li-ion battery itself. These full cycles just help the smart battery charging circuitry and the battery level meter/gauge to better calibrate themselves. A few times a year is probably more than enough to keep the battery gauge from going way out of calibration.