Developing your specific style is something I have been very aware of since college. There were many students in my class that had found their own specific way of illustrating that suited them... I had no such style. I often latch on to a single style for a short while but then begin to experiment with something else. It is wise for an illustrator to keep a specific look that would be recognizable as you, probably a maximum of 2. For people who know my work they can see that is mine, usually through the subject and the way I hold my pencil but when it comes to how much detail I use or the medium I this often changes, even dramatically.
Maybe soon I will come across something that will keep me exited for a long while so I can at least develop a collection.