Black is deceptively simple. That is, it contains alot of complexity if you know where to look. When doing black, the first thing you have to ask is...what TONE of black? Or, with what color will it be highlighted? The two most common black tones are grey and blue.
If you like a down and dirty "i've been fighing in the trenches" black then I would suggest highlighting with codex and fortress greys. Darken or ligten to taste.
For a glossy hight tech look I think Blue shading is best. You must darken the blues to makeit highlight evenly.
An easy way to give a further tech look is to use some magic wash. This will give it a bit of a shine without being overpowering.
Just my 2 cents.
ender502