If you want to use a picture of you (or something that you have) make sure that the quality of the picture is good and (most important) be creative with the photo. For example: make a selection of some objects that you love (like a perfume, a bow and a portrait of you) or take a picture of you with a t-shirt made by you that says "click here!" , think outside the box and you will see results soon. :)
Some more tips for a good user image:
Use strong colours - Strong colours aren't discrete at all, so it may attract many users. If you make some unusual combinations of colours it may attract even more users.
Fashion images are always good - When you use fashion images in a fashion site, of course you will be more appriciated, however, pick them well. Runway images aren't the best to choose from, it looses the details and looks confusing in a smal size. Photo shoots are a better choice or a tribute to a fashion designer could be even better.
Use photoshop - Sometimes the image isn't quite perfect, so making a couple changes in photoshop will make it better. You can make everything in there so be criative.
Use creative pictures of your idols - It's great that you have idols that you love so much that you wanna put them as your user image. But I need to be honnest, sometimes it can be boring. Again, be creative and show to the world why you love them. If you like Lady Gaga or David Bowie (as I do), seach in the web some illustrations or collages of them, there's some really great work made by very talented people. Or you can do it your self.
Here's some examples of good images: