This type of brushstroke layer can be guided by drawing curves for the flow direction or marking parts of the mesh to define flow/break edges and faces to be ignored using the shortcut Ctrl+Alt+F. Draw; Draw brushstrokes as curve geometry directly on a surface mesh. There are settings in the toolbar as you draw to control, for example, the color. More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.