Take a breath. Here are a few tricks...
1. Go for what your PASSIONATE about. Think of what you are most curious about as a career...sometimes an internship shows you what you DONT want to be...better to learn now, then when you've already got the job and a pile of bills to pay.
2. Start early and SEARCH, SEARCH, SEARCH. Once you've got an idea of the direction you want to go in, delve into the research. Check the blogs: there are a number of blogs that alert fashionistas to the best of the best in internship opportunities. (fashionista.com talks about all sorts of fashion internships & ed2010.com is strictly print and magazine jobs)
3. CUSTOMIZE YOURSELF! Think of all the entries HR has to go through, show them something different, make a personal cover letter for every entry, add some flare to your resume (but keep it professional), and be yourself on the interview...I hear that over and over again from employers.
4. Most of all...DONT GIVE UP! How many times do we hear the uber successful say "You have to prevail", "Don't give up", "Don't take no for an answer"? Sometimes you may not win, but ask yourself why? And work on that. Whether they give you the opportunity, or not, send a thank you letter, it shows that you are thankful, dedicated and humble...who knows, I HAVE heard of people going from the "No" to the "Yes" pile just because of a thank you letter making the difference.