Figure out who your desired target audience will be. Primarily girls? Boys? Both? Choose a specific subject you are familiar with and build your magazine around that. Examples include fashion, skiing, photography or a specific region or state.
Decide on the format you want to work with to publish your teen magazine. A hard copy can be very expensive; you might want to consider an e-zine. Then, when you have a sizable audience of readers you can work your way into paper copies. (See resources)
Create a dummy issue: This is crucial if you are creating hard copy issues. Figure out how many pages you want your magazine to be. What will your feature article consist of? Do you want an advice column? Book, movie and music reviews? Photographs? An advertising section? Divide off sections with a ruler if desired, and write in "photo of dog," "article on dog training," etc.
Sign up with an inexpensive stock photography website such as Shutterstock or Microstock photos. These resources have thousands of photographs you can use to make your cover and inside pages eye-catching and interesting.
Invest in good magazine publishing software. If you are short on funds at the outset, you can start with a basic program such as Microsoft Works, but you will soon want to graduate to something more suitable such as Scribus or Pagemaker.
Create your final copy. If you are working with on online format, you can check the FAQ section for helpful hints. If you are creating a hard copy to have printed, check your work carefully for typos. Use a good quality printer for the first printing.