This article is from the Miniatures Painting FAQ, by Brenda Klein email@example.com with numerous contributions by others.
Finest brush you can get, a steady hand, lots of patience, and good
lighting. Fine detailing includes (but is by no means restricted to)
faces, eyes, jewelry, shield devices and banners, small clothing
details, weapon decoration, insignia, and armour detail. For many of
these, some of the highlighting/washing/drybrushing tips above apply,
for others a whole new range of techniques are necessary.