It's kind of by necessity. My approach is to print nearly everything on the same paper. It's kind of like the bolt in the hole thing where if the bolt is the wrong size it's loose or it won't fit. Think of the paper as the hole and the negative the bolt. If the negative doesn't have the right tonality it won't fit very well with the paper's tonality. That's the whole idea behind getting the most out of a film - to tweak the exposure and film processing such that it gels very well with the paper. Simple idea, and I find it easier to start with the finished product and reverse engineer my work flow rather than trying to jam the tonality of a negative onto an array of papers. To know what to expect makes for a lot less frustration in the darkroom, and a lot less waste.
Mamiya: 7 II, RZ67 Pro II / Canon: 1V, AE-1, 5DmkII / Kodak: No 1 Pocket Autographic, No 1A Pocket Autographic | Sent w/ iPhone using Tapatalk
~Stone | "...of course, that's just my opinion. I could be wrong."~Dennis Miller