My Process is a little different to most - so my Mini's always go through a "messy" phase.
Deathstroke has had multiple shading washes, Army Painter Strong Tone Ink, left to dry and then followed by Army Painter Blue Tone Ink, then a final (after drying) Army Painter Strong Tone Ink wash. These were thinned slightly (as usual with Airbrush Thinner rather than water).
After that a VERY light dry-brush of dark Grey - this helps show all the details.
The "plates" in Deathstroke's Armour was painted Army Painter Plate Mail Metal - and then, when dry washed with (you guessed it) thinned Army Painter Blue Tone Ink.
Early Days yet, but you can see where I'm going with him (I hope). I'm going for the more metallic look, which appeals to me - and I'll more than likely use Army Painter Greedy Gold with an Army Painter Jumpsuit Shader wash for the Orange Plates and Side of the Mask.
I'm trying a TOTALLY different Look with my Blackgate Prisoners Set One - basing them around this picture.
As you can see the more violent Criminals sport dirty white Coveralls, as opposed to the classic orange of the General Population.
So far I've got the basic blocking in, and the first "dirtying" wash - I need to start working up the highlights, through a dirty white, to a final highlight of Vallejo "Off White" (I rarely go to pure white).
Last we have the High Security Henchman - again, I'm staying away from the Orange - the look of him to me says he's ready to be transferred to Arkham, so I'm going for red Coveralls.
Still, there's so much more to do!