If I remember my Colin Fletcher (MHRIP) correctly, this is what he did back in the seventies (sixties??) for his tarps. Worked well then, should work well now. He used it regularly, I think it may be best used as a field repair if the original grommet or tab pulled out.
He who sits alone, sleeps alone, and walks alone, who is strenuous and subdues himself alone, will find delight in the solitude of the forest.