one difference between barcelona and berlin is the fact, that you can search for flats online - if you are able to act quickly or have a ticket in the pocket at the right time. it also helps, if you have a chance to get an overview of the market in advance. in order to avoid to get mucked by the price check the berliner mietspiegel.

i never understood why you need two washbasins, a shower and a bathtube in one bathroom, until i read that they can ask for more money by doing so.

normal candidates to screen are immonet, berlin morgenpost, immobilien scout, planet home, immowelt and some of the co-operatives.

but often cheaper, at least where you can find flats without a commission are private or students lists: studenten-wg, wg-gesucht, opusforum, loquo, ... (use google for more); last one offers flatwise more for barcelona than berlin.

what you then need is a partner to talk with, to keep you running and reminds you about reasonable specifications you once set up.

if you find something, call immediately and talk in detail about the flat, especially if you deal with private owners. if you deal with agencies ask them to sent you the floor plan and if other flats are coming in.

we have been in berlin in august, but that wasn't a good month to look for. now it took us one week of intense screening online, a lot of luck and a weekend in berlin to get a flat without paying commission, renewed, wooden floor, at a price of ~5euros per square meter, warm and in a nice district. count four days to finally sign the contract.

ah, before i forget: germans seem to believe that everyone is a criminal first hand. you better prepare yourself in advance with all kind of papers; if it goes smooth you need a letter from your former/current landlord and a proof of income.

next thing to come: internet connection ...