I pretty much only use acrylics for everything cept the glossy items.
I use tamiya XF-1 (flat black ) as a base then mix some XF-1 and XF- 64 ( red brown ) to make a wash ( diluted heavily in either water or alcohol ) then wipe it on liberaly, after it dries go over it in pastels for rust and maybe some pastels for dust/grime pending on a field model or a track park kinda scene?