What an exciting thing to find this community! I'm not a cartographer, but just the other day I told my wife that if I couldn't be what I am for a living (I'm in the software business), I'd be either a bottom-end tennis pro (I'm not that good, but probably just a little bit over the bell curve), an itinerant musician (a little further along the bell curve), or an amateur cartographer (I could spend all day looking at maps). I love all three pursuits. I imagine they'd all pay about the same, and I'd be equally spiritually fulfilled in any of the professions.
In any case, I'm recently thinking deeply about maps because I am working on a special project that concerns mapping; more specifically, I've decided that fractal mapping generation software sucks. Sorry to break it to any fractal terrain generation enthusiasts. But I have driven through, wandered around, and flown over (staring out the window) large portions of three continents, and fractal map generation is only believable at a very small scale.
The problem as I see it is roughness vs. smoothness. The roughness and smoothness of natural terrains is based on more factors than any algorithms out there yet can believably approximate. Some of these factors include plate tectonics, weather patterns leading to erosion, and of course human impact which starts at least ten thousand years ago...possibly more (as an example, native americans on the eastern coast of north america were burning large tracts of forest as part of their hunting strategy long before europeans arrived).
So I believe the best generation of fantasy maps is still the province of the artist/scientist, not the algorithm. And the only level at which fractal terrain generation is believable is the local - I have yet to see an algorithmically-generated world or continent map that stands up to scrutiny...Usually within three seconds you can say "That is computer-generated!" Of course if you want a very low level first-person view from within - let's say - a fjord, you can probably tweak your generator to give you one...but it won't include the cobblestone beaches, or the strand-line of dried tree trunks washed up after the earthquake-generated tsunami years ago...
I'm also interested in the human side of it: mapping of hamlets, towns, cities, city-states, nations. And again there's a level of believability in the visual depiction of these polities that can't be achieved without the consideration of multiple factors: how and why would people have settled there in that way....how did that settlement develop into that thriving metropolis, and why? Was there a natural deep-water port? Was there a natural barrier against invasion? A large amount of natural resources? Answering these questions makes for a more believable map than just painting a large settlement onto a piece of coastline.
A good cartographer is an intuitive geologist, natural scientist, ecologist, anthropologist. I have a hunch that most of you are most of that. I look forward to sharing maps, giving and receiving feedback, and learning from you!