Kevin,
We have a set of clear cut policies written out and signed by them when they move into the unit. (My favorite is: We do not do tenant drama.)
We use our phones to take a video of the property with the tenant when they move in to document the condition of the unit along with a written report that the tenant signs and gets a copy of.
We automatically withdraw the rent from their checking accounts on the 25th of the month rather than the 1st. This allows us time to pay the bank on the 1st and gives us a head start at the courthouse if we need to go that route.
We respond to and handle maintenance requests as quickly as is possible.
When a tenant notifies us that they are moving, we send out a packet that describes how we want our unit returned to us (same condition as it was provided to them upon move in as described on the written report above). The packet also contains a list of costs that will be charged to the tenant if the stove is not clean, if a light bulb is not changed, if a fork is left in a drawer, etc. We usually get our units back very clean.
Hope the above helps you,
Kevin