Manager here, I hire a lot of people from unskilled to managerial level. Without knowing to much about your individual situation it's hard to comment specifically but I can give you some tips, if you do this stuff already then it's probably just bad luck. I've been exactly in your position twice, aiming for different industries. In both I've gone from the mail room (literally) to the top floor in two years. i say this not to show off, cause who cares anyway, but to show it worked for me at least. My writing style is brusqe so just bear in mind I'm talking generally, not specifically about you.

1. size up each job you apply for carefully, don't just send off a generic CV, tailor it to each job. Remove irrelevvant details. We don't care that you like dogs, unless you're applying at a vets etc. Do include anything relevant no matter how small. If you're over qualified, shit just don't tell them if you think it will count against you. I doubt anyone has ever got in trouble for downsizing their talents. Do include a photo on the front page (small). It'll help them form a picture of you. If you tailored your CV right you are now 3D to them.

2. Always include a typed, job specific cover letter. Don't wax lyrical, just spit out the facts... i want this job, I'll work the hours at the wage you set, i won't complain, I won't be late, I won't take sick days unless I'm dying.

3. Turn your CV and letter into a PDF before you send it. or don't, but it's better, whatever.

4. If you've got an industry in mind aim for ANY job in the vicinity. once you're in, anywhere in, its a lot easier to jump around.

Check your emails and keep your phone handy, aim for half a day reply by email and answer that phone quick. Make sure you got credit to call back and check your voice mail. The world doesn't wait for you to get back to it.

The CV stage is the most important, because so many get cut here. We screen the CVs fast and weed out the non-starters. CV's got errors or is not a close fit, gone. Notes extra conditions of employment (hours, wage etc), gone. Shitty attitude evident (I get a lot of people telling me how they were fired from thier last job but its ok it wasn't their fault), gone. And lets cover that in more detail, some people seem to view it as an insult that I would want to screen them, this job should already be theirs. Don't be like that, they don't need you as much as you need them.

OK so you've got your interview, this requires more judgement.

1. Gauge your interviewer(s) carefully. Are they formal, are they relaxed....are they insecure or stupid! You are not selling yourself in all your glory, you are selling what they want to see. If they want to hire a young over-achieving go getter be that. If they want someone who just does the job and won't outshine them, be that, if they're dumb make them feel smart. I can't tell you how to act, but remember to swallow your pride and be the employee they want. Sometimes it will suck, but you want that job right!

2. Dress tidy but appropriate (a suit is not always the answer believe me), don't smell, blah blah blah. Applying for a customer service job? take that nose ring out. I took my piercings out, boom, job offers. I just put them back in when I got home.

3. Try and politely get questions about the job in before they start questioning you, details about the job description ie tasks and hours etc. Do not ask about pay or benefits yet, thats after. It gives you some more info to tailor your answers, and it gets them talking so you're not so on the spot, you can build your rapport with them before having to go on display. Use the time to assess the interviewer as well as the job.

Now at this point you got a decision to make, how long are you intending to stay there, probably not long. But they do not want to hire again in 3 months right. So are you going to lie and say you're there for life and then fuck off, or do you say you're there for 2 years and actually do it. Up to you really, whatever moral trip floats your boat.... But this leads into the next point.

1. You want THIS job. It suits your hours, your ambission, whatever. If you tailored your CV right and have sold the image it will look right. You are essentially lying but you've really got to sell it.
   

After you're out of there you can't control it so just hurry up and wait. If they ring and say no, be polite, say you're available if the situation changes and move on. You'd be suprised how often you only just missed out.

If you get it, don't let them regret it. work hard, don't be late all that shit. Moving on up is another much longer post so meh. but if the above doesn't get you a job in a month or two I'd be suprised. And yes it does take that long, but once you're in hang on to it like grim death until you get a chance to jump to something better, and make sure your landing is clear before you jump.

Good luck, hope it helps.