I put Poser away for a year and am just now doing renders again. Don't wait that long, then you need to learn the program again...lol
Take a walk outside and really start looking at things, even a small rock can kick up a render in your head. I also have a book in my head and two others that are fighting to get out, I write on all three as they come up. You will find that no matter what you think of, someone somewhere has done it, just put yourself into yours to give it that uniqueness that you are looking for.