My place is centrally located and connected to all public transports. In the heart of the gay area with lots of cafes, bars and restaurants and at a stone's throw from the famous KaDeWe and KuDam for shopping and tourist attractions.
I have no particular rules. Politness, friendliness, respect and understanding are enough.
You also must have no problems with dogs because they live here and they always greet my guests and have access to the whole apartment (apart from your room).
And due to some problems with pick pockets I no longer allow my guest to invite visitors over. After all it is a private apartment.
P.s. if you loose the keys it will cost you 100 eur to be paid before checking out.