Oooh, cool, a pro! Are there any examples of your work you can post, WhiteRaven, or at least link to? We always welcome input on how the real world does things, with the caveat that fiction can get away with being way less precise than you're no doubt constrained to be on the job :-). Do you do imaginary locations too? What kind of tools do you use? Having worked once upon a time in the software end of GIS/carto (Intergraph) I'm painfully aware many pro tools are beyond the reach of occasional mappers - both from money and time investment standpoints - but some of our pro Guildsmen have provided tips workable on the cheap.
So welcome, and well met, sir!