I use smoke as the base for 99% of my weathering on a/c.
I tried pre shading panel lines like most people, but it never looked 'right' to me, then I tried post shading with Tamiya smoke through the airbrush and have never looked back since.
One thing to remember when using smoke for weatehring, it should be applied
BEFORE you put on your flat coat, and when properly thinned it gives excellent results, and being a light tinted colour, you can apply the right amount of weathering/staining every single time.