I have led a confusing PDN journey, because I drifted in and out from it. I was turned on to it early 2007, and began experimenting. I only had the few plugins that came with the program, but I was excited with what I had. Then the same friend told me about the forum and how he used it for the tutorials, and I joined that May (the month, not a typo).
So, I am not technically new, but I haven't been on since late 2007 really. I just got back into it after graduating high school, and enrolling at the Boston Architectural College.
But, I still stick with the simple, which is experimenting. Rarely do I have an idea in mind as I create. I just render, and blur, and distort untill I am pleased with the result. The upside of this process is some funky looking stuff, and when I actually do have a plan in mind, I use what I previously learned to incorporate into it.
So, even not being a pro by any means, if I were ever offer any advice: Experiment! If you get an artist's block: Experiment. Bored: Experiment. I have come up with a few nice works because of it. (Oh, and the tutorials section of the forum is a big help to!) Happy PDN'ing!