When conventional interviews aren't working, What Color is Your Parachute is worth a shot.

It has something called the creative job search. The basic idea is instead of applying to a whole bunch of jobs, you work out the job you want, and get that. It's solution selling, rather than job begging. You are a product - who needs that product? Who has problems that you are the solution to? After all, employers have problems, that's why they want to hire someone. They aren't actually interested in judging or evaluating you (or shouldn't be). They just want a solution to their problem.

You look at your skills (including other skills in your life) and your knowledge (e.g. terminology for that field). You then work where you would love to work, where those skills are needed. Then you find ways to contact those people - not sending a resume, but talking in person.

At first, you might conduct some "information interviewing", where you are trying to find out more about those organizations - would you, in fact, actually enjoy working there? What is the work like? You can ask anyone who might know about that field/organization - it doesn't have to actually be a person working there. This incidentally also improves your "interviewing" skills.

Finally, you discover the person who has the power to hire you - note that most HR dept etc are there to screen you out, to find reasons to not hire you. If they have hundreds of resumes, they may start by throwing half out without looking at them. So, go directly to whoever can hire you.

Apparently, most jobs in small businesses are filled via word of mouth, not by advertised positions. (You should target small businesses because that's where most jobs are created). It happens like this: the boss has been thinking of hiring someone to do some particular tasks, but it's not yet urgent, and he hasn't got around to it. Then you turn up, and you're such a good fit that he creates that position for you. NOTE: this means you have no competition.

Now, because you are actually interested in using these skills, in this field, for this particular company, you will come across as genuinely interested, eager, maybe even passionate. People like that. And it's hard to fake.

In an actual interview, your task is to address their concerns. These are:

why are you applying to this company?
can you basically get the work done, be trustworthy, on time etc - i.e. can you solve our problem?
what special qualities do you have that set you apart from everybody else (it might be related to an entirely different part of the job/company).
Will you fit in here?
Can we afford you? [ note: this implies that many places might really benefit from your skills, but can't actually pay a fair wage for them ]
Obviously, this is a whole lot of work. And the guy in the article might not have time left in the month to do it comprehensively. But it's worth thinking about, and maybe incorporating some of the ideas that appeal. [note: this is all from memory, and the bits that appealed to me personally, so of course it's best to refer to the book itself.]

For me personally, following those 5 points in a cover letter has always gotten me a job. (along with seeking jobs I actually would like). I think they really help me see it from their point of view - that we're all really just trying to solve a problem here. We're on the same side.