Most of the time I use a pen or pencil and notebook which I carry everywhere with me, as the Muse doesn't hang around my desk.
I prefer to scribble down anything and everything without too much thought (it invariably gets in the way). This is a sort of free-flow conceptual stage where it's simply about the 'idea'.
Later I enter it on to my computer and tend to find a title and a few key sentences in amongst the mind-mess that was first thrown on the page. This often takes care of the title and chorus. From then on it becomes work.