Thanks for the comments
Sjefke:
AB = airbrush
Abrasives - whatever is to hand, but a mixture is always good! If you want to create paint fade from gradual wear and tear, use finer grit - particularly useful on wing and panel edges. Coarser stuff is great for topical scratching, scuffs and scars. Scalpel, wire brush, Scotchbrite, Brillo - all useful. I only really use paste abrasives to cut back gloss paint where I want it hyper-shiny on car bodywork. It would work really well for doing extremely gradual fades and knocking the brightness out of colours like reds if you went at it a bit more.
The soot and drips were all done using wet Tamiya Weathering Master on this kit. These come packaged (and actually feel similar to) eye makeup - even down to the applicator they come with. They seem to be very slightly oily and stick more readily than pastels or dry weathering powders. They also hold up better to varnish. Apply them dry for a dusty, powdery finish, apply them wet for greasy/watery/oily and darker finish. You can get some nice effects by hitting the stuff with a fine mist of water from an airbrush after application.
Don't try to do too much to a model too quickly. Build it up in fine layers in a controlled manner and have an idea of the amount and finish you want to achieve before you start. It is mostly an additive process (you're putting paint or pigment on to the model to simulate dirt, grime and soot), but don't forget that it is also subtractive - paint, grime and muck gets scratched off or smeared in places. Go back and weather the weathering occasionally. My favourite part of painting models I have to say. Great fun and incredibly forgiving
