Creating a desert in Bryce is more difficult because you can't rely on your water to make your scene look cool. We like to work with camera angles, haze, sun/sky settings, and textures to make my scenes really pop. Experiment and have fun!
The River Valley is one of my favorite Bryce landscapes for two reasons:
1.) It amazes me how much you can do with a simple mountain.
2.) Simple changes (like the angle, textures, and sky) make a huge difference in how it looks.