Just began using Poser Debut and these are just quick, unembellished drafts I came up with. I know I have a long way to go so criticism and tips are welcomed.
Even simple props & scenery can transform a scene and there are plenty of free ones on renderosity & sharecg. I've posted some stock props I've made on TickleTheatre.
Try changing the camera focal lengths for some interesting shots and set up your lighting by turning the other lights to 0 and the one you are working with to 100 or so.
Most of all make lots of mistakes and don't get discouraged.
Fun start! Lots of great resources out there, good luck to you. Smade is right, Renderosity, Sharecg and also DAZ has plenty of free resources. Have fun with it as well!