1. Choose the right magazine for your purpose. Think about what it is you want to promote and to whom, and then choose the magazine that caters to that audience. If you want to sell your art workshops, how-to books, or DVDs to your fellow artists, you want to be in artists' magazines, like American Artist, The Artist's Magazine, and International Artist. If you want to sell more of your paintings, you'll want to be featured in collectors' magazines, like Southwest Art and American Art Collector (although you have to buy an ad to get featured in that second one). And remember that collectors can be found anywhere so broaden your reach to magazines that cater to people who may be interested in your work because of the subject. For example, if you include your favorite sock puppet in every still life, contact toy collectors' magazines.
2. Pitch the story and get a green light before you write (or worse, pay someone else to write) the article. Editors do not want to receive pre-written articles. In fact, they'd prefer to consult with you on the content of your article before it's written. They might even want to have a staff member or freelance writer of their choice write the article. Even if you do end up writing it yourself or hiring someone to write for you, don't invest any time or money into writing the full article until an editor has agreed to publish it when it's done.
3. Write a convincing pitch letter or e-mail. The key to getting published is to convince the editor that a story about you or the group you represent will be great for the magazine's readers. You do this by sending a pitch letter that explains a) the original "angle" or subject that you can provide, b) how the information will benefit the magazine's readers, and c) why your credentials make you worthy of space in the magazine. You do not want to write, "I would love to be featured because I could really use the publicity." The editor already knows that it would benefit you--he or she wants to know what's in it for him or her. The editor's job is to please the readers, not to promote you, so your pitch should be more along the lines of "My journey as an artist is fascinating to collectors" or "I can teach your readers a new technique I've developed." If you want more detailed info on developing an angle and writing a great pitch letter, visit the "writers & writing" section of any bookstore or library where you'll find plenty of examples.
4. Follow the instructions when submitting a proposal. The pitch letter is just one part of an overall proposal package that you'll submit to the editor. Other pieces may include examples of your work and your bio or resume. The important message here is to visit the magazine's website and hunt around until you find their info on Submissions or Proposals or Submission Guidelines or similar. Once you've found their instructions, follow them to a T. If they want it electronically, send it that way. If they want it by snail mail, send it that way. And send everything they ask for and nothing more. If you absolutely can't find any guidelines on their website, check the masthead for the name of the current Managing Editor or Assistant Editor, and send him or her an e-mail asking for submission instructions. Don't contact The Editor, that name at the top of the masthead. Save that for the actual submission.
5. Be patient in waiting for a response. It's not unusual to wait a minimum of three months before you get a response. If you haven't heard by then, send a brief, polite e-mail or make a brief, polite phone call to the Managing Editor or Assistant Editor, asking for a follow-up.
6. If you'd like to contact competing magazines (magazines with the same audience and probably the same readers), do it one at a time. Start with your favorite/most promising one. Only when you've heard a definite "no" should you move on to the next one on your list. And never, ever agree to be featured in competing magazines at roughly the same time. It makes the magazines look bad, which damages your reputation.
Okay, that's all I got. Be proactive. Be patient. Be persistent... And make it fun!