I am just going to post some quick comments and examples from my own experience. This is by no means meant to be exhaustive, and there are plenty of sites to review if you do a Google search for "photographing miniatures".

Focal Length, Focus, In-plane

How you set up your lenses and how close you position your miniature affects the depth of focus of your camera. A shallow depth of focus causes the effect where a portion of the object is in focus, but the rest is not, especially if you are focusing on the nearest feature. The quick and dirty solution is to move the object farther away (so you are sampling more of the object when focusing), switch to a wide angle lens setup, and/or position the object so that less of it projects into or out of the plane.

Both images were autofocused at the center of the model. In the left image, the model is projecting into and out of the plane more, so the ends of the model are a little more blurry than the center point (in that case, the left thigh). The right image, in contrast, is mostly in-plane. Canon Powershot G1, Auto setting, Macro on, maximum telephoto, Flash off, 2 diffuse light sources from right and left (24" away from model) and camera 12" from model.

You may also be constrained in focal length. For example, in the picture above, I used the maximum telephoto setting and the macro lens feature. This setup required a minimum distance of 7.9" between the lens and the object. Any less, and it was completely blurry.

Lighting

This is the most critical issue I deal with, it seems. The trick is to diminish excessive glare due to finishes and achieve a lighting effect such that the details and colors are as faithful as possible to what one would see with the naked eye. There are a couple of ways to achieve this.

First, you want to avoid glare - the bright spot of a bulb will reflect off even matte-like finishes, depending on the setup. The chief way to mitigate this is via a diffuser. For those of us on the cheap, we can use a desk lamp with a paper towel over it. PLEASE REALIZE THAT THIS CAN BE A FIRE HAZARD, DO NOT LEAVE THIS UNATTENDED!

Economy diffuser - cheapo swivel arm lamp with Chromalux 60W daylight bulb and paper towel taped over opening.

The angle and intensity of illumination are important as well.

Overhead illumination - 3 Reveal 60W  bulbs covered by slightly smoky glass.	Zero overhead illumination, minimal front bilateral illumination - two swing arm lights out in front to the right and left, rotated so the bulk of the light does not shine on the model, Chromalux 60W bulbs.

Heavy front bilateral illumination - Two swing arm lights with Chromalux 60W bulbs out in front to right and left, bulbs pointed directly at model, bulbs 36" from model. Although details are somewhat visible, the shades of purple and green are far lighter than they look to the naked eye.	Same as left image, but with diffusers (paper towels) in place.

Moved the bulbs to 24" from model. This is very close to what it looks like to the naked eye, although the highlights are still a little artificially washed out in this picture.

And here's the exotic, high-tech setup. Two swing arm lights with Chromalux 60W bulbs and paper towel diffusers, positioned to the right and left, and less than a foot above horizontal. I use black velvet as a backdrop (a box underneath creates the back wall) and the mini is positioned 12" from the lens (the mini was on top of that magnet/film case in the center of the backdrop.

Speaking of backdrop. How important is that? Read on...

Backdrop & Lighting

The backdrop of your photographs can have a tremendous impact, especially if you have a high tech camera that optimizes light and color. Here are some pictures of some freshly stripped metal minis, a comparison between Pine-Sol (left) and Simple Green (right). This is the sort of picture where light can be your enemy. In this discussion "bright light" refers to a primarily direct overhead light (standard incandescent dining room fixture) and a diffuse light off to the bottom left of the image (halogen torchiere) at maximum intensity; whereas "dim light" refers to only the torchiere, reduced significantly in intensity (inadequate for reading). Now, you can adjust white balance to change this, but for my purposes, I would rather set everything up such that the auto settings work like a charm every time.

Bright light in room, white office paper as background. This is pretty close to what it really looked like to the naked eye.

Bright light in room (same as above), black velvet as background

Dim lighting (to the human eye) with black velvet background.