One of the big debates that people seem to get confused is having a design style vs approach. To me a style is what you come up with from the approach to completing a project. Because if you want to design a poster in a swiss design style then you would have to learn the principles and then take an approach to come up with a similar style.
Your style will mold itself when you continue to work on your approach to projects. The way to improve your approach is to practice thinking about how to approach the project differently. The approach could range from doing things differently then you normally would to designing in a different place.
So with this said do not worry so much about your design style. Style is something that everyone seems to want to have. Your style will develop overtime through looking at more design and designing more. Your approach will develop the more you look at how you are working from beginning to end.