Question of the day: Do people send magazines unsolicited material? Do they look at these or do they advertise for articles on whatever they cover?
Unless you're sending in an essay for consideration (or travel piece), you should never send in a completed article. Rather, you should fashion a well-researched pitch with an angle designated specifically for that magazine. A service piece on the latest research on depression, for example, will need a different bent for Parents vs. Self vs. More vs. Men's Health. They're not going to advertise for this, as they're inundated with pitches to begin with, many not well-researched or well-written or well-thought out. Instead, you should really familiarize yourself with the magazine your pitching. When I was really at my height of freelancing, it probably wasn't much of a coincidence that I had the highest success rate and highest enthusiasm for magazines (and assignments) of mags I actually subscribed to. I understood their voice, their story angle, their tone, and I could match my queries accordingly. If you read a magazine for long enough, you get an idea - even just as a reader - of what they're looking for.
Which isn't to say that all long-time subscribers can break in. They can't. They won't. But it sure as hell helps to know that, for example, Family Fun seeks specific activities/locations for your family, and differ from other parenting magazines in that way. (I cite FF because I remember, before I read them, that I almost DID send them a parenting query that was better suited for Parents, until I started reading the mag and realized how quickly it differed from the others.)
This sounds like basic info, I know, but you'd be surprised how many writers don't take it to heart. READ the publications you want to pitch. SEE what they're printing and then find new, exciting angles and ideas to bring their way. That - along with good writing, a lot of hustling and yes, a touch of luck - is what will help you break in. Good luck!