What weathering techniques do you plan to use?
Dry brushing, "washes" to highlight panel outlines, rust, and that sort of thing, all by hand of course. I'll "whiten up" the center of the roadwheels, then "muddy" the whole wheel, rubber and all. It's kind of a painstaking process, but it's amazing how grungy you can make the thing look without all that much effort, it just takes a little practice and patience.
In this pic I've done some very basic weathering.... a thin wash was applied and allowed to run along the skirt joints to highlight them, some smudges were added sparingly, and a couple of simulated bullet/shell strikes were applied. I might add some rust later.
Things are coming along nicely now, and tomorrow I will apply some "rusting" and maybe add some light dirt/mud to the roadwheels, then I will paint some of the detail parts like the Muffler, tow chain, gas cans, spare tracks, shovels, jacks, and so on.

Gen. George S. Patton Jr., 28th Regimental Colonel, 3rd Armored Cavalry Regiment, U.S. Army, "Blood and Steel"