For the reason that David pointed out, I type out my lyrics in Excel as my mind is too jumbled when I'm coming up with lyrics. Writing it down on paper just gets too messy.

With Excel, I tend to have a list of ideas or lines in a right-hand column that I'll move around and try to fit into the main body of lyrics that I'm assembling in a left-hand column. I find it easier to do that in Excel than in a Word document.

Now, when I'm free-writing to get some ideas for a song, I might write out some ideas with pen and paper, but I'll also do that on the computer; whatever I have closest to me at the time.

Also, when I'm learning a cover song, I'll write out the lyrics by hand as I've found it helps me learn the lyrics more quickly.