Here's an orc from Tin Soldier painted in a somewhat retro style with heavy blacklining in ink.
Although I had originally based many of them on pennies, I've decided to put all the 25mm RPG figures I've been hoarding on 20mm square MDF bases (if the figures are roughly human sized). That renders them more easily usable in wargames too, and means that groups of figures can be bluetacked neatly to larger bases for Hordes of the Things and Kings of War and the like: so six of these orcs could fill a 60 x 40mm base to be a 'horde' element.
Having most figures based in the same way means more versatility and cross-compatability. So hobgoblins in 25mm can be mere goblins in 28mm, and brightly painted 25mm knights might serve as diminutive elf-knights in 28mm, and so on. I find square bases a bit more useful than round bases, all things considered. I can't think of any game system in which round bases are mechanically significant. The same's not true of squares.
I'm also increasingly interested in the idea of switching between RPG and wargame modes in the same campaign (using a 1:10 or 1:20 figure scale for the latter), something that square bases facilitate. So square MDF bases all round it is - with the exception of plastic rounds for 28mm sci-fi and plastic fantasy skirmish figures, and pennies for 15mm sci-fi.
