The best way to go about it is to start finding what inspires you. You can't just flip through magazines and advertisements for your inspiration, you've got to find inspiration everywhere you go if you want to be truely successful at fashion photography. You can be far more successful if you go into a shoot knowing exactly what you want and what you need to do to make this happen, so prepare everything in advance, especially when working for a client!
Don't forget that though fashion photography is creative, and beautiful, it is also a commercial profession. As my fashion teacher, Nino Rakichevich, used to tell us, "clothes has to look good!"
**NOTE: All photographs used in this tutorial were shot and retouched by myself, including those that have the Vogue logo as they have been published on Vogue.it
Step 1: Fashion Checklist
Probably one of the most important aspects of fashion photography is the styling. It is extremely important to work with a stylist for your model's clothes. Stylists can come up with ideas that you never would have even thought of. They know what looks asthetically pleasing and know what jewelry, shoes, bags, and other accessories would make the whole outfit stand out. Some photographers are able to do the styling themselves, so lucky them, but if you're really serious about fashion photography, either hire a stylist for your shoots or learn the ins and outs of current and vintage fashion. Be sure to have multiple outfits to create a fashion story. When have you ever looked at a series of ads and seen the model wearing the same outfit in every shot?
Location is also extremely important. Yes, fashion can be done and be successful in a studio setting, but there still has to be something about the image that makes it stand out. A fashion photograph taken in a studio with nothing interesting to look at is not successful at all. Have you ever been looking through a magazine and just keep flipping pages until something catches your eye and you stop and take some time to look over that ad? That's what your fashion images should do. Location is a big help with that as it sets a theme or story for the "narrative" of the product, (yes, products can tell stories).
And of course, lighting. Play around with it, don't just keep using the same lighting over and over again. Create shadows and textures and shapes to give the image a mood or make the product stand out. Some clients may ask for a high-key image, which is fine, you definitely want to do what they are looking for, but when you have creative control, be sure not to overlight your images. Sometimes, one light is all you need to set your mood. Generally, if you're using flat, even lighting for fashion photography, you are shooting a lookbook, if there is more mood and theme, you're shooting editorial. Both have different purposes, but both are very important in the industry. Remember, the product must be the most important part of your photo.