What I always try to do is to respond to the song; I've always rebelled against theory.
Mark KnopflerI used to go to the school folk club with my songs when I was only 13 or so and say "this is a traditional folk song" and sing it with a bad Irish accent to disguise the real source.
Mark KnopflerWhile listening, to things like western swing, for instance, I'd work something out in my head, then play it on my National; not the same song, but one that captured the feeling of the original tune.
Mark Knopfler