Some owners bypass the agents by displaying a banner across the balcony facing the street. The banner advertises that the apartment is for rent and gives a contact phone number. My brother in law does it this way though he's got nothing vacant at the moment. It saves a lot of extra expense and complication for both parties by cutting out the middle man though please note most owners - including him - will still draft a legal contract and still insist on the usual guarantor. If you haven't already, it might be worth your while walking through your chosen neighbourhoods with your eyes looking up!