1. Backup funds.
Make sure you have an emergency, reserve and float funds, this funds will help you when ever you are in an emergency and you don't have finance which is what is needed, instead of dipping hands into your Bitcoin by selling it you can just us your backup funds to settle the emergency.
Having a backup funds will reduce the emotional pressure to sell during market downturns also.
This is the only viable point I can think of, and the back of funds should be more than enough to cover the seen and the unseen (emergencies). To achieve this rightly, it is even beyond mere extra funds, but having a viable source of income to fall back at. If you have that, I can assure you that you can save your Bitcoin.
Fulfilling this, the only condition that could be pressing as well is your belief in Bitcoin. Not that a little bearish movement during the determined selling period would make the person liquidate the Bitcoin.