Heres what I have used in the past.
Take a clean pump sray bottle, a bottle of liquid RIT dye Black. or DARK grey. Deluted with HOT water until it is a dark transparent shade. Adjust the sprayer to a FINE mist and standing at few feet Let loose with a fine Mist. allow to dry between applications.
This has worked well with My Boots and my Jump suit.
On the Pockets and places where Fett would have touched is suit, Like Pockets and such I dirty up those areas a little heavier as dirty hands/ Gloves would soil the suit more in those parts. as well I beleieve that having a JET pack on your Back would cuase the areas in the rear to get filthy from Exhuast Blast. take a look at the Boots wes has up The MC boot on there has been weathered in this fashion. Just MY 2 cents
