I used to be a journalist, albeit reviewing books (and for a short time restaurants, as a food critic

). Although I've not worked as a video game specialist, I've still learnt a few things that might be relevant for you. Here are my top tips, for what they're worth:
1.) Apply for jobs. APPLY FOR JOBS! You need to keep close tabs on the vacancy situation at every publication that might even be slightly relevant, and apply like a shot if anything comes up. Or even before; you're unlikely to be employed just by sending something in, but if nothing else it may have a positive effect if you ever apply for a vacancy.
2.) Don't become a crazy 'employment stalker', though. That doesn't really create a good impression.
3.) Focus on the quality of your writing, as that is what would hopefully cause you to stand out from the crowd. Think hard about clarity, detail and how useful your reviews are.
4.) I'd say that sites like this are a good idea -- but with qualification. Shmups.com is full of educated individuals, but the range of games covered is very narrow. Conversely, the problem with places like GameFAQs is that they are full of total idiots, but the advantage is that they cover games of all genres. You don't want to paint yourself into a corner, genre-wise. If you do submit reviews to this site, you should also be submitting reviews to a good quality pan-genre site, at the very least -- and by 'good quality' I mean somewhere that ideally isn't full of clowns like GF is.

Someone who only reviews shooting games is not really employable; you have to have a broad portfolio of past work.
5.) Writing for local papers and so on is a good idea -- even if you have to offer your services for free. There are quite a few local rags that always need more good quality content and are correspondingly more likely to accept your (well-written) work. It might be Shitsville Weekly, but a review in print is 100 times better than one that's just on your hard drive.
6.) Finally, it is indeed about luck -- but there's some truth in the saying that you make your own luck. So get out there and do it!
Good luck.
