Well, for me, so far anyhow, I still consider myself more an artist than cartographer and that's because I am more interested in drawing and painting than I am concerned about precise GIS information.

That said, I would like to fake it as much as I can. I think most viewers are more interested in a map that sucks them in and allows them to get lost imagining what all those areas and locations must look and smell like. That's what I want to accomplish for the viewer anyway. I figure at some point I will be able to create what I envision more or less perfectly and then I will want to start making sure I understand all the serious real world details and so on but until then I'm not going to let realities get in my way

Obviously, hanging out in a place like this you can't help but start to pick up some of this stuff thanks to some of our more serious GIS type folks.

As far as scales go I think that often rivers are faked because they wouldn't even show up on the map otherwise. Personally, I like to show river locations and the scale is more about how far one city is from the next or how many days it will take to cross a mountain range. For a role player this is important to know and since I figure most my maps are for that purpose... If you measured the river using the scale however it might actually look like it's a half mile wide or something ridiculous. I'm ok with that but I try not to have it look too out of whack.