Little bit more painting tonight (don't panic Doug, I am still painting as well!)
But took the time to do a little analysis of those first three heads, before I do the next batch.
Ok, so the positives, looks like I will be able to do it, I can achieve the detail I'm looking for working at this scale, which is hard to gauge from the photo's, but isn't huge (the heads are in reality only about 4-5mm high)
However, it's also apparent I haven't got it quite right yet.
So assessment of what I think I've got wrong:
1. The heads, well at least the first two are too long, they look stretched just a bit too much. Now I do want thin faces with character, we're not going for a modern "huge pumpkin head" look, so that's ok, but I think I've gone a little too far. Having said that, I haven't added the things that widen the head out, like ears, hair etc, neither have I added the top of the forehead/hat, but even taking this into account, I think a little less elongation is called for.
2. The third head is better in this regard, but it's probably too far the other way, and also the nose is too fat. That added to the "frowning" look makes it all a bit scary (might be good for a "charging/aggressive" figure though!) I could probably fix the frown by adding more of a forehead, but the nose isn't going to get any better.
So slightly less length and chin, go steady on the nose, I'll try that with the next few and see how they look.