Painting patterns on clothing folds?

Well, Im going to try a 54mm Celtic Warrior, which can be seen here:
http://cgi.ebay.com/A17-Celt-Warrior-V-b-C_W0QQitemZ6027174483QQihZ009QQcategoryZ2634QQcmdZViewItem

Anyways, Celts often wore brightly colored cloth into battle, with stripes and plaid and other such things. I really want to recreat this effect, plaid would be too har,d so maybe stripes or checkers, but how do you do it realistically over the folds on a figures clothing? I know how to mask but I dont think it would look right.
Heres an example of what I mean: http://www.coolminiornot.com/28570

Also, on the first figure, on the "scale" ype armor on his chest, would that be leather or metal? I thought it would look cool painted metal, and since celts in that period didnt all ahve matching armor, I thought jsut about anything would be realistic, but should those be leather or metal? Thanks.