Happy Seppuku is a new company (at least new to me!) that sells basing texture and detailing kits. Their molds allow you to make impressions of various textures in greenstuff and other similar putties which are used to finish off your bases. Those at the top are two of my favourites. In the past I've defaulted to outdoors sort of textures, but with priestly figures and the like I'm thinking that interior textures might be more appropriate. I especially like the Old World flagstone texture at the top, only I wouldn't paint it a solid colour. I remember seeing a tutorial on the Manorhouse website where he showed how he used a mix of colours to make a much more interesting look.
For our up-coming Swamp Folk I think a ships decking would be perfect for their bases. Something like that shown below...
