A question that is often asked of artists is, "What is your personal style?"
Personal style is a lot of things and definitely not some things. My personal style is not based on subject matter as an example. I do not limit myself to taking photos of any one thing, flowers for instance... it is not my style. :)
My images, my personal style, is more emotional than anything. Perhaps fortuitous, from the standpoint of unplanned. However, fortuitous, usually implies lucky... I do not consider it luck... I consider it "Spiritually" guided. This is not to present an elevated opinion of myself... anyone, and I do mean anyone, can be "Spiritually" motivated or guided... you just have to have the heart for it. In essence, you must learn to see with your heart as much as with your eyes.
I do not limit myself to color or to B&W. Some images to me convey a deeper meaning, a deeper emotion, in one format over the other. Saying that, I really love when an emotion is strengthened through a rich B&W print. Perhaps the result of working for years in my own B&W darkroom... perhaps because I value subtle shades of gray and definitive blacks and whites in photography as well as in my faith.
Speaking of subtle... my personal style is one with a strong background in "straight" photography with subtle modifications to bring the image back to how it was pre-visualized before snapping the shutter. Working with RAW files allows me (and dictates) that I modify the image somewhat. I also believe in cropping an image where necessary. Very rarely does a camera, any camera, present an image exactly how it was pre-visualized by the photographer. Post processing your RAW file is, necessarily, part of your style as it directly relates to your pre-visualized image.
I concentrate less on the technical aspects of photography when capturing an image and more on the feeling... something that happens only after you become so familiar with your camera and the settings that it is almost automatically an extension of a "heart guided" unthinking, physical action. There is a very strong temptation to set the camera on full automatic so as to concentrate on that "feeling" but you must ignore that temptation, take lots of photos, get to know your camera and the mechanics of photography, so that procedure becomes automatic using full "manual" on your camera. The camera is only a tool, like so many other tools, and it lacks the emotion necessary to define you and your style as a photographer.
I believe in simplicity and beauty in the common (even the unlovely). I believe that the weak can be made strong. I remain hopeful in the direst of circumstances. All of these things help define my personal style.
A photographer's style is directly related to how he/she thinks (more importantly, how they feel) and how their experiences have molded them to grow. As a photographer grows their style may change but it is always influenced by their complete history.