This page was posted on another forum....thought it might be of interest.
The text is in German, but someof it can be understood by pictures and interpretation (or you can have google translate it for you)
http://www.ph-modellbau.de/tips__tricks.htm#Effekte (http://www.ph-modellbau.de/tips__tricks.htm#Effekte)
Yes it is armor, but the techniques/ideas translate just as well to RR. Even if one does not agree with all the approaches/techniques...it still can sperk an idea.
Marc