well, I'm not exactly a pro when it comes to photographing mini's I do have some tips for you:
Use a white sheet of paper and hold it like this: (quick example made on paint
this way you'll have a nice background for photographing, and it makes the mini's pop out a little better.
Next is the lighting:
Use a daylight lamp, with a sheet of paper hanging in front of it to dim it down a little. (don't put the paper straight on the lamp, because the lamp might get hot!!!) This gives a very good light to photograph with.
last but not least: use the miniature mode (a flower icon) on you camera. (dont know wether your camera has it, or wether you've used it, but this one really reveals a lot of details on a photo.)
when using those hints you'll probablly get a photo like this one (I used mij Nokia N95's camera for this one
I know it still isn't perfect, but it sure looks good, and the background isn't very distracting
(and the shadow on the background makes him looks a little more evil IMO, but you can Photoshop that away if you want ;)
Now on to the mini's:
I really like the mini's you have! The only thing I don't really like is the soul grinder's head, it just looks too small IMO.
I do have a question: which head did you use for the Daemon Prince??? And which wings? They look very nice