Not quite sure what you mean. Do you have an example? Which way should the lines be going? Horizontally? Vertically?
For reference, I am a *very* amature painter. I know what drybrushing is, and I know what washing is, but beyond that I have very little skill or knowledge. I have heard *of* things like non-metallic metallic and that light-source thingy painting, but I wouldn't have a clue how to do it.