Successful interaction with a tenant.

[Tyler Warne]

I just bought my first property, a fourplex and one of the tenants is smoking inside. I set forth the new rules, as I was sure that the last owner was not caring. This tenant responded well to the request but then has continued to smoke indoors. What are some successful measures that professionals have taken to have positive outcomes? Tell me your story for this or other difficult to enforce "rules". Additionally the tenants upstairs really do not like it. 

-Tyler "too nice novice" Warne