I just figured out how to improve my coastlines in inkscape, using the calligraphy tool rather than freehand drawing... I apologize if this is "duh" obviously known to everybody but me, and I also apologize that I can't be bothered to type it up twice and instead shamelessly redirect you at my blog for the details.

http://enderra.com/2012/09/07/better...with-inkscape/

:-)