I tend to start off at about 850x600 (the max recomended setting for Bryce on my pc) for the early stuff, but then my early stuff is mainly just boxing out and adding models as I do them. As I get closer to the end I'll up its size though to get a better feel for how it'll look. Final renders are about 2500-3000 pixels across-ish, depending on lighting rigs ;)

Dreams are just nightmares on prozac...
Digital WasteLanD