Everyone has a different workflow. I personally have all my "Ink" in one big group, then divided into mountains, forests, icons, etc., and have "Colour" in another group. This is a more traditional comic book style of drawing keeping colour and ink work separate. Definitely learn how to use the pressure settings, they increase your drawing ten fold. I went from thinking "my drawings ain't half bad" to "I am a master artist!" when I got my wacom (albeit I'm not a master artist in any sense of the word, but that's what it suddenly felt like ).

The key really is time, effort and details. You can tell when someone got tired of doing a map because they left out the little things that make a good map into a GREAT map.