There are few places where an employee can smoke these days. That being said this is an important policy as it needs to cover several issues. Firstly be sure to reference that the policy is in concert with state / city guidelines, as well as those set forth by the building. To this end, be sure to learn exactly what these guidelines are. Next focus on where smoking can occur, again referencing building policy. Lastly, and in general terms, reference what frequency you see as acceptable.