It is indeed time-consuming, but actually i'm pretty happy with the copy/paste elevation method. It has a way of including interesting details that i hadn't intended, which makes it more fun, and increases the authenticity of the final product. Of course i still have my larger, more complicated continents remaining. The true test is to see how much of my enthusiasm remains for this method at the end.

I've more or less completed two of my smaller continents. I don't think it will be nearly as easy as i feared to spot the terrestrial origin of the pieces i "borrow". IIRC i used 4 pieces of Earth (plus one for the island on the right)-- anybody care to guess which ones?

Radial gradients are a great tool to pitch the elevation of an area in the direction you want.

Click image for larger version.  Name: Echo-elevation.jpg  Views: 676  Size: 257.3 KB  ID: 23761

P.S. Interesting thing i've observed. Lots of imaginary maps have continents with mountains roughly in the middle, but earth doesn't seem to work that way. Almost all the main watersheds are jammed up against one side of a continent, usually with a smaller watershed opposite.