So, I'm clear on the concept of using a dry brush with very little paint on it as a way to subtly tone areas. I have just tried using this technique on a 1/35 armor model and was quite successful at getting the bolt heads, hinges, etc. to "pop out" from the main model. However, I also ended up dry-brushing the flat areas around the bolts, which just looks sloppy.
So, I'm looking for suggestions about what I did wrong and hopefully ideas on how to do it better the next time. Thanks!