@boy wundyr x: I'm hoping to get a mini photo tutorial up soon, but here's the general outline of what I do. I'm using these for tabletop use and not regular wargaming (solo dungeoncrawl kind of thing), but here goes:
(A) Have a really, really tiny brush – I use one of the detail brushes from Reaper.
(B) Make sure the paint you're using is liquid. Thick paint will cause frustration.
(C) Use an elevated surface/wood block to get the piece close to you and brace your hands/wrists.
(D) Don't paint detail that won't be seen. What I'm doing is totally overkill for large area wargaming. Think about the distance between the players eye and where the figure will be.
(E) Deliberately rely on washes for bring out detail.
1. Glue the figure to a small cork (I usually buy a bag of these at a crafts store, but anything similar can do) – this allows you to comfortably hold the individual piece while painting.
2. I use a thin wash of paint right on the bare metal (this isn't 'best practice', BTW, but the detail is so fine on the 6mm figures that a standard coat of primer could cause me to lose some of it). This initial wash is brown (if a human or light skinned creature) or black. This'll bring out the detail and make it visible right away.
3. I usually do a base coat of flesh over the exposed skin parts. If it covers over the initial wash, that's OK
a second wash is coming
4. I look at the garments and items carried. Base coats for both but making mental note of where the brown/black initial wash indicates detail.
5. Another wash for the skin's shadows/recesses.
6. Washes for items/garments.
7. Highlights and Details
I mix a slightly lighter version of the base color and apply it to outer/upper surfaces. I don't always do this – if it isn't going to have an impact at all, just skip this step. Many 6mm faces don't have that much detail but a single, very gentle stroke can highlight a nose or upper cheeks. I may put some touches of detail
8. Metallics are last
Testors, baby. A little shine goes a long way but try to make this the last step. When I'm holding these under my desk lamp and painting really close, I notice that the 'glare factor' is much greater on smaller scales (i.e. my eyes literally lose the ability to make out detail if the glare is too strong)
this is another benefit of doing the initial wash. I could not use Testors gloss enamels because the glare was too strong. For figures wearing armor, you may want to use a small but stiff brush and try gentle drybrushing or lightly stroking on silver/steel over a chainmail or armor texture on the mini.
9. A last look to see if any areas have been missed.
That's the basic idea, but the steps above are broken up over a few nights, so I'd probably say that between each step, just let the paint really dry on its own.
Also, doing multiple figures in each step is something I always do. I'd go nuts if I could only work on one figure at a time.
The steps above are also an extreme case. I've only painted a few 6mm figures so far, but some figures can skip one or more of the steps above.
The glare thing probably caused me the biggest problem, and then practicing getting Testors paint to make washes.
I'm still new to this
what's above is adapted from 25mm painting and model building from my youth.
Sorry for the long comment!