I like to mix washes and bases of different colours for natural variety. Eg yellow with brown wash, grey with sepia wash.
like badgersplatter says and finish it with a very fine highlight. I like that better than a dry brush but that's also a good alternative if you don't want spent time on fine line highlighting. but if you do that and you interrupt in a irregular way the fine line now and than instead of one continued line of highlighting, that will even look more natural.
This is a Dark Age, a Bloody age, an age of Daemons and of Sorcery. It is an age of Battle and Death, and of the world´s ending. Amidst all of the Fire, Flame and Fury it is a time, too, of Mighty Heroes, of Bold Deeds and Great Courage. William King