"Then there's people who've take a slightly different career path, or chosen a job at some unknown place, yet have lots of good experience, and they're ignored because HR doesn't know what to do with them..."I've been that guy on more than one occasion. I'm a self-taught hacker, and I made the mistake of majoring in English in undergrad. While I usually look great on paper at the hiring manager stage, I have pretty spotty luck with the HR filter. To make matters worse, I've graduated twice into very unfortunate circumstances: 1) I graduated from college into a recession (post-tech-bubble-burst); 2) I graduated from grad school into an extremely deep recession.
The necessity of my circumstances has forced me to get creative with my job searches. Hence, the "modular resume" strategy I outlined in a subsequent comment. And hence the general strategy I now take on all job searches. Conventional wisdom holds that a job search is a numbers game: get your name out there as broadly as possible, and eventually, you'll catch a few things in the net. In my case, knowing that I look iffy on paper to HR drones, I know I need higher-touch tactics. Casting a wide net won't get me many fish. I need rod and reel, so to speak.
So I'll hyper-prioritize, say, 10 openings. And then I'll really drill down on them: researching the best fit, reaching out to friends of friends, doing informational interviews, networking over a fairly long term, etc. My goal is to get the hiring manager to know me before my resume hits the HR filter. I'm dead in the water if I hit the HR filter blind. (My affinity for horrible, acquatically themed metaphors knows no limits).
In fairness, a lot of these tactics could be seen as good habits in general. But for me, they were born of necessity. So in some ways, I enjoy being an unconventional candidate. It forces me to experiment, to learn, and to adapt, and to persist.