When I first started painting miniatures, lighting wasn't a thing that people did with miniatures. OSL hadn't bee invented yet, fire was painted with the deepest red at the center, and people didn't consider a light source when they highlighted their minis.
Miniatures were only painted to emphasize their shape- recesses are shaded, and highlighting goes on the outermost areas, rather than the top most.
It was actually a pretty effective method for emphasizing details. However, if you look through pictures of current top painters, you'll find that they pretty much always paint everything with at least one source of light in mind (some painters will have several different colored lights shining on the mini from somewhere off stage).
And it makes a big difference.
Doing this for the first time is about training your brain to know where shadows go. One method Rhonda Bender told me is to imagine your mini in the rain. The areas that get most wet are the lightest, the areas that would end up staying kind of dry are your shadows.
Here is an example:
As you can see, the light is coming from above her, and just a little to the front (I picked a direction that would help me emphasize her face. I think it is most obvious on her legs that about half of her is in the shadows.
Another thing to note is that the turtle is keeping light off of a lot of the plants underneath her. I base coated and shaded those areas, but I didn't add in any of my highlighting to them, and this creates an interesting difference where the light is able to catch on some of the edges of the plants.
I find that it is simplest if you base coat your mini in mid-tones, then shade first and highlight up second. This method creates a clear line between what goes in the shadows and what goes in the highlights.
The first few times you do this, you will feel like you're leaving the mini half finished. Again, the biggest trick here is re-training your brain to just leave something alone when it is shaded and done. And ultimately, it really adds a sense that your mini is in a place, and tells a great deal more story than before.
