Whilst the article highlighted below is aimed at tenants. the suggestion that photographs should be taken at the start and end of the tenancy equally applies to landlords. 

Photographs, along with a detailed inventory, will assist in evidencing the state of the property prior to the tenant moving in and at check out. This will help to establish the level of damage, if any, for which the landlord and/or tenant are responsible for under the tenancy agreement. This, in turn, will reduce disputes relating to the tenancy deposit.