The reason many travelling people don't use Couchsurfing, are the prejudgements.
Is it safe? What if I don't like the host or surfer? I don't want to be forced to spend time with them. Will I meet their expectations? Are you REALLY sure it's safe?
These are EXACTLY the questions I had in my mind about 4 years ago, when I was deciding whether or not to inscribe myself. I wasn't planning to surf yet, but living in Antwerp, the most beautiful city in Belgium,I figured I could start hosting some people. Of course I was a bit preoccupied, I was living on my own after all, and if somebody would kill me it would take some time before my body would be discovered... - and YES, this was exactly what I was thinking, I am not exaggerating! Though, I talked with some friends that were doing it for a few years, went to camps, hikes, events, hosted and surfed, and I decided I should give it a try. Of course, you don't let no matter who in in your home, nor do you go surfing at the first host that pops up in the search. That's why I decided to make an outline about how to find the perfect host, or how to evaluate the fit of that surfer that is asking if he or she can stay with you. The principal is the same for both in my opinion, since the goal is just to get along as well as possible, and have the right amount of privacy and social contact to both sides' wishes.
1. References and friends
First of all, references are a safety check. These are actually the experiences of other people on CS with this person, and are highly informative. To get a negative reference is quite strange, unless you do something really unacceptable. Most negative references are posted because of people getting stood up by their host - which of course questions their reliability, (sexual) harrassment or surfers not complying with the house rules.
For me, one negative reference would not be a reason to not host or surf with someone, especially if he has many other positive reviews. Though, to be honest, if I have other options with people who don't have negative references, I'd probably go with those ones. Friends on the CS profile might be people that the person already knew outside of CS.
2. Age and gender
This is a quite important feature, again - mostly for safety. CS is a very openminded community, and age or gender should not be a reason to discriminate hosts or surfers, though that in the end you usually do want to meet people with who you have things incommon, and the age can be a good reference of this. It's quite logical that when you're 18, you will have more incommon with younger people, than with someone of 45. Since CS is such a big and diverse community, I do recommend to set up a - more or less flexible - age group for the people you host or surf with. I am 24 at the moment, and for me, people between 20 and 35 seem to be the most interesting. Of course, if some nice 18 year old student writes me a really personal request, and I can host him, I will not refuse it, but it serves more as a directive, rather than a law.
Other subject is the gender. Personally, I prefer hosting girls or couples, but my first Couchsurfers were Joan and David, 2 guys from Barcelona. Didn't you think about safety, you would ask? Well, honestly, that first time I didn't. I had an amazing time with them, we went sightseeing, out for dinner, party, ... and had an amazing time! They invited me to spend New Year with them in Barcelona, and when I moved to Barcelona for a semester for my studies, they even helped me find an apartment. The most wonderful first Couchsurfers I could've wished for! Anyway, to get back to business, you might consider starting with hosting girls only if you're a girl and you're living alone, and when you'll feel yourself more comfortable inside the community, also host guys. When I am surfing, on the other hand, I am more focused on the place I will actually sleep in - than on the gender of the host. In general, there are way more important things about a person than his gender only, like the references, personal description and the way they talk to you.
4. Personal descritpion and interests
Everybody has the chance to make their profile as filled up as they want to. Not everybody likes to describe themselves, but I think it's a quite important feature when you select your host or surfer. It reflects their interests, way of behaving, and also gives you a clue if you could have interesting conversations together while hanging out, or rather not. Of course, if you're merely offering a place to sleep - or looking for one, this will not be the most important thing you'll be worrying about. Though, if you're expecting to spend some time together, it might be good to read their profile and judge if you'll be a good match or not. Opposites attract, unless you have nothing in common to talk about.
I should not tell you that surfers or hosts are not supposed to be picked by their superficial appearance. Though, it gives you a good idea of the person, and personally it is one of the most important incentives to stay with someone - or allow someone to stay at my place. I am not talking about beauty, but about charisma and the aura that people irradiate on picture. You can be the ugliest person on earth, but still, if you have a good heart, you will see that on pictures! CS pictures are a way to show people who you are - not how beautiful you are. Therefore, I don't trust people who don't have at least ONE normal picture, where you can clearly see their face. I might be judgmental on this one, but I don't get people who post 10 pictures of them with sunglasses on, on 10 different locations. I think one picture of your face should be enough, at least so the people would recognize you when you're standing at your door!
This is very important, since you'd want to understand what your host or surfer is saying. Communication is a crucial necessity while surfing or hosting, so you have to make sure that both of you speak at least one mutual language at an intermediate level to be able to talk decently. Even the CS system will warn you when you're trying to send a request to a person that you don't speak a mutual language with.
7. Couch information
This is of course in case you are surfing yourself. A private room is the best you could wish for, but this happens quite rarely. When I surfed my friend's Donnie couch, we had a small room for ourselves, including including covers, pillows and everything we could wish for, which was really cool. Though, usually you can only count on a couch in the living room, you might need to bring your own sleeping bag and/or towels, or you might even have to share a room with your host. Everybody should decide for yourself what your limit is, but personally, I don't see myself sharing a room with a person I don't know that well.
8. Couchsurfing is NOT a free hotel!
What you should avoid, no matter if you're hosting or surfing, is to make CS seem like it's a free hotel service, since it is not! It's about meeting people from other places, and getting different cultural experiences. When you're hosting, I highly discourage accepting people who write short or copy-pasted requests to everyone, or who clearly didn't even read your profile. There are a few tricks to prevent this, like putting a secret question or a password somewhere in your personal description, but I think a normal person can see if the surfer writing you has or hasn't read your profile.
When you're surfing, it is highly appreciated to spend some time together with your host, and even bring a small souvenir from the country you're coming from. This already creates a bond, and is more likely to end up as a successful CS experience.
So, I hope you guys have a more clear view on Couchsurfing now, have a little bit more of faith in its safety and consider using this amazing way of travelling around the world!
And, from my own experiences and other CSers that I know, I want to add...
You never know if the man or woman of your life, your soulmate or new best friend is waiting for you on Couchsurfing! :)
Greets from Gypsyland,