Best practices for landlord to breaking a lease?

[Mike Finn]

Hello everyone! Question - I have heard/read about what happens when a tenant breaks a lease (loss of security deposit, paying rent for a number of remaining periods, etc.) but what happens when a landlord decides to break a lease? What are best practices for doing so? How many months warning should you give the tenant so they have time to find a suitable place? 

I know that breaking a lease is not ideal, but what should a landlord do when it becomes necessary?