I take the notebook route too. I have one and any time I think of something interesting I write it down. I have stuff in there I wrote down one or two years ago. With that song Always You, I found a verse I wrote at some point last year, and the rest just came to me. A good thing to do is, when your almost asleep, write down the incoherent random thought phrases that pop in your head. Pretty much, any time you think of something you think would be a good song line or idea for one, write it down and you can refine it later. The more you write stuff down the more natural it will become, so do it often.