If you want to have every chance to succeed in finding the temporary home of your dream on couchsurfing, you will have to follow scrupulously a few basic rules.
1)The first one is certainly one of the most important: don't be lazy and avoid copy-pasting the same message in order to send it to a bunch of people who have absolutely nothing in common! This is the kind of details almost every proprietors on couchsurfing complain about. Imagine how annoying it can be to receive the same type of request from people who obviously didn't take the time to write you a personalized message. A request that can be send to several different hosts is simply a bad request. Hosts need to feel that something special caught your attention (and not only their pretty apartment). If you really want to find someone who will be truly happy to have you, you should take the time to check the profiles of the potential hosts in order to find out something you could have in common with one of them. For instance, if the host you're interested about studied theater in university, tell him/her that you noticed a common passion for theater and that you would be pleased to have the chance to meet him/her. To sum up, the first thing to do is to find out a hobby, a passion or anything you can share with your potential host and to highlight it in your request.
2) Secondly, never confess in your first message that you are broke! Telling your host immediately that you're down-and-out is going to send him/her the wrong signal. The proprietor will think that you're doing this only to save money and you'll pass yourself off as someone greedy who doesn't care about the human side of the experience. Remember that Couchsurfing isn't only about saving money and getting a cheaper accomodation during your trip. This is also and above all about creating human contact and your host will feel used if you forget that.
3) Thirdly, always check the references of your host: This is one of the important things in Couchsurfing. To fully enjoy your stay, you need to trust the person who will host you, and the best way to know it is by checking his/her reviews to see wether they are mostly positive or negative. You should be abble to read at least 10 references on the profile. Be careful, there are some cheaters who create fake profiles in order to fill them out with only positive reviews! To be 100% sure that the profile you're checking is not fake, check its references and then examine the profiles of people who wrote them. That way, you will easily determine the validity of a profile and avoid being very disappointed. Last little trick to spy out fake profiles: they usually don’t have any references at all and they have a very short bio.
4) Of course, do your best to be kind and courteous with your host, by bringing for example a little souvenir from your country: Despite the fact that Couchsurfing is not a website with which you are paid for hosting, it is always very pleasant for an owner to receive a little gift from their guests. Again, you don't want to have a bad feeling with your host which could possibly ruin your stay, so don't hesitate to show that it's important for you to build a positive and respectful relationship with him. Think about getting him a specialty from your country that he won't find anywhere else. Why not bringing a good bottle of alcohol if your host likes having a drink from time to time? It's always nice to share a good bottle of wine to become acquainted with somebody and it usually helps to get a good conversation started!
5) Be sure the address you have is correct by checking it on a map and/or on the internet: The best way to avoid losing your new temporary adress during your trip is to learn it by heart and to visualize where it is located in the city you're going to. Depending on where you're going in the world, don't forget to check on the internet if the region you're travelling to is safe for foreigners. It's always very important to know if there are some precautions to take in the city or the region you're flying to. Finally, don't let yourself be surprised and ask your host before leaving where you're going to sleep and if it's a shared room/bed or not.
6)Last but certainly not least, never mix your host’s home up with a hotel: There's nothing more annoying than a guest who forget his manners by thinking he is renting a hotel room. As we said earlier, hosts share their houses not only to help you spend a good time in their city, but also to meet new people they wouldn't have met otherwise. Spending some quality time with your host and getting to know each other is part of the game. At last, if you go out late, the least you can do is to let your host know the time you think you'll be back and to ask him if it is not disturbing.
I hope these tips will help you to find a safe and warm place which will make you feel like in your home in Istanbul.