Use harder-edged brushes at 100% strength. Keep the strokes visible, not blended together. http://wiki.polycount.com/wiki/TexturingTutorials#Painting_Stylistic_Textures
As a 100% remedy for this lack of functionality you have to use createDialog test_dialog style:#(#style_resizing,#style_titlebar, #style_border, #style_sysmenu) with some subrollouts in it.