I'll confess that I don't paint as much as I should and certainly I haven't painted any armour for a very long time. However, this week I finished a couple of Arnourfast T35/76 that were assembled last summer. This was mainly an exercise in weathering techniques and to try out a few ideas I'd seen discussed on the internet.
I then loaded up a stiff brush - one of the cheap nylon ones for children you get from IKEA and, using my thumb, sort of flicked the thinned paint in various places to simulate mud that had been thrown up onto the tank. I may have overdone this a bit but it was fun. The last thing was to add some more black wash around the exhausts.
Overall, they have turned out OK although I think that a little more contrast would be good. Next time I'll make the black wash a bit thicker and add more rust spots - the detail isn't that deep on these models so more contrast between dark wash and lighter highlights will be required. Also, I will add a bit more detail, hawsers, tarpaulins and whatnot and might even paint on some suitably stirring slogans - I did try it this time but couldn't paint them small enough so that the words would fit.