Sounds like a daft question, but if the point of marking it is to help you identity your ball then you'd have to mark it in such a way that it was likely that you'd know your ball regardless of how it had landed eg deep in the rough so you can only the top of the ball. In that case putting multiple lines round the ball might work but putting just a single mark on one side wouldn't.

Or do you mark your ball ever so lightly so that if it is in the deep rough you get an opportunity to take it out to identify it and then put it back in a slightly better position?