As a working musician who is also a working music journalist I've made friends in both fields of the music industry, so I feel I have something to offer to this topic outside the traditional methods.
The number-one thing to consider when approaching a journalist is first-contact. Do you want to make first-contact via e-mail or snail-mail (which still works, by the way) or in person?
If you choose e-mail, be concise, professional and personal. A professional music critic receives so many e-mails a day that he or she can't keep up with them. A short personal note up front just might be the trick to being remembered, because then they will feel the need to respond.
If you choose snail-mail show them your handwriting somewhere, like a note in the margin of your press release, to grab their attention away from what they are used to seeing in the typical press release.
If you choose to make first-contact in person, congratulations. Actually meeting a music journalist in person for the first time is like a trifecta when it comes to scoring good press. It becomes much harder for someone to ignore you when they have actually met you face-to-face and shaken your hand.
The thing to remember upon meeting the music critic is that the critic is a music geek, just like you. State your name and what you do but then proceed to talk about OTHER music besides yours. They will remember you then. After that FOLLOW UP. The follow-up is the key to getting press. They don't care about you, but you do care about them, so FOLLOW UP (this tenet involves exchanging contact info, which should go without saying).
Outside of meeting the writer in person, do your research. The first major press I ever received as an artist came from researching the tastes of the three music writers in my local paper. I realized after doing the research that only one of these writers would be into my music. I sent a personal e-mail inviting him to my show, opening for another act he had written about in the past. Upon meeting the writer after the show the first thing he said to me was "I never would've come out early to see you if you didn't send me that e-mail."
Do you see where this is going? No matter how you make first-contact with a music journalist you should make it personal. Let them know you are a real person, not just another of the ump-teen-thousand acts trying to make themselves out to be something they're not. Let the person you are contacting know that you know who they are and not just receiving spam from you.
Which brings us to the next big question: phone calls?
Unsolicited phone calls from unknown bands are perhaps the best way to send your new CD submission to the pistol range for target practice (it happens, I've been there). This goes against everything I've told you in this article so far about being personal, but the truth is that most music journalists don't want or need to be bothered by an incoming call from a act they've never heard of. Try the methods above first and if they don't work, well, just keep working at your craft and wait for them to come to you. That happens, too.