In anticipation of working with my Otherworld miniatures, I've surveyed websites and blogs devoted to painting and basing. In the day, I just glued my citadel miniatures into their slotta bases and away I went. I had zero concern for mold lines, light and shade, and aesthetically pleasing bases. There was no LGS (or internet) to go to and learn about this stuff either.
I did notice though that a number of folks had really spiffy dungeon floor or cobblestone bases for their miniatures that really added a nice finishing touch. Sure, I could keep it simple (and cheap/er) by gluing and painting ballast on the bases, but normally stuff is happening in dungeons, crypts, etc and woodland bases just didn't seem to make sense. I've experimented with ballast bases on some pre-painted EM-4 minis, and that was fine but not what I wanted for my Otherworld miniatures.
So I found the Back 2 Base-ix store on Ebay and ordered several lots of round "Dungeon Stone" and "Cobblestone" bases in 25mm and 40mm. Now, these aren't low maintenance. You have to remove flash on almost all the bases and I had to sand the bottoms flat (don't breath in). Then you have to wash them in soapy water. Be warned, there's a fair amount of work to be done even before you get to priming.
Despite the work involved, I would recommend Back 2 Base-ix. Aaron is very friendly and helpful. The bases come from Australia and, at least in my case, were shipped very quickly. I'm looking forward to buying more. They have free shipping until the end of April.
Here's a look at some of their bases. These are the style I intend to use: