Applying for a fashion internship is the first hurdle. Magazines, especially successful ones, don't just hire anyone who applies. Prove you're worth the time and the mentorship. The easiest way to do this is by sending a professional-looking resume, and even going a step further by submitting a cover letter. Yes, editors may not read the latter—especially if they don't ask for it—but you never know who will. A cover letter may even be the deciding factor if it's well-written, interesting, and an attention-grabber. This also shows you take initiative and are willing to go the extra mile. Whatever you do, do not make shit up. Be ready to talk about and back up everything you include in your CV. Check for spelling, punctuation, and grammatical errors as well.
Send a professional-looking resume and cover letter.