Something I like to do as a sanity check is to draw my gross features on an actual globe prior to making a projected map. You can get a styrofoam sphere from a hobby store or check the ball bin at a Wal-Mart for something in a solid light color, or even simply a balloon.

It's difficult to free-hand a projection from that, of course, but it's at least a starting point to see if what you're doing makes any kind of physical sense.

Or you could use a digital 3d paint solution. I'm not sure what's out there at the consumer level, though. I have access to all sorts of cool CG animation software like ZBrush, so I've never bothered to see if something like Sketchup lets you paint on geometry.