Besides Bryce and Poser I use Photoshop a lot, Picture Publisher, Universe, and recently Terragen. I work on a Pentium II PC with 256 Megs of RAM, a Riva TNT graphic card and a small Acecat III pen tablet. Well, for one I never use Poser textures. They do not work for me. I create a model, import it in Bryce as a dxf file, and texture it directly in Bryce.
Lighting is very important, vital.
Light will sculpt a scene or flatten it. A same object, no matter what its texture, will look completely different under various lights. I always remind myself that the eye never sees the object itself, only the light that bounces off it. That's my 'secret'. I bought the software, read a few books, a few tutorials, talked to a lot of artists, and got my feet wet.