As a fashionista  you have probably noticed that most successful designers have their own style sense and point of view that is unique to them.  Their style of design would have ultimately been branded in them in the market. Studying them will  help you to develop yourself and see how one builds their style.
A signature look is a key part of branding.  That doesn’t mean you don’t evolve.  Fashion is always changing and designers must change with it.  But designers  still have an inherit look to their collections.  Burberrys is not going to be doing Betsy Johnson flashy prints and Vivienne Westwood is not going to make preppy Lacoste shirts.
But here is the thing: Your own style isn’t something you can come up with from today to tomorrow. Usually your style will naturally evolves as a fashion designer. It is a process and one that you need to go with.
Sometimes I have clients who are really not sure what there style is and for them I send them to the stores or internet to research.  Putting together ian nspiration boards of photos, fabrics, colors, and trims that resonate with you is a great way to help you define your style.
By following this process ideally you  will end up with a look that is unique to you.  Everyone looks at things with their own creative filter. Each designer’s process is a little bit different from everyone else. However, sometimes we begin to mimic, too closely, other work without realizing it. Make an effort to make your design your own with its own DNA.
We don’t need another Tory Burch or Kate Spade or Lululomen.  Those companies already are successful.  What we need as an industry are brands that have their own personality and creativity that inspire and delight customers.