Anyone know of a good grey tutorial

[Death 0F Angels]

I am having trouble painting grey cloth and i was hoping someone could point me in the direction of some good tutorials. I am not having a problem with Cadian legs or the cloth on the forgeworld torsos but i flunk every time i try to paint the catachan legs. I tried googleing it but any search i do comes up with page after page of grey knight bs.

[Psychosplodge]

I'd suggest start dark and work to light the same as any colour layering guide like for cloaks and such?
Definitely can't help with colours though as never really used grey.