I have a motto that I use a lot, "You can always say no". It's really great advice if you are looking for a new job but keep turning down interviews. You should never, ever turn down an interview if you are looking for a new job. Not related to your current job? Take it. Not really in the industry you are in now? Take it. Interviewing for jobs is the only way you can be sure to really, truly find a job that makes you happy. Here is why:
You don't know what you don't know - How do you know you don't want a job if you don't interview? Need I say anything else? Really, if you don't take the time to talk to people you are letting preconceived opinions and biases influence your decision making. Stop doing that! Take the interview, learn as much as you can and make a decision based on the facts.
Practice makes perfect - Interview much? Most people don't.....so most people aren't good at it. So, what better practice than the real thing. Seriously, think about how much more relaxed and "on" you'll be when you have an interview you REALLY want if you've had a few practice interviews over the previous months. Plus, see tip above.
It's all about the network - Not the right fit for a job? Decide to pass? That's ok, maybe the person you met would be a great future contact or lead for you. Sound like a long shot? It's not, I've got a few folks who I've interviewed with and now keep in touch with professionally as well as personally (HUGE shout out to Sanjay here!)
So that's it, take the interview. Doing this will allow you to make decisions on jobs based on the facts, meet new and exciting people and fine tune your interview skills for that job you really want to get.