The best way I find, is to have your music written, then take a guitar or whatever and play the verse chords over and over and over and just hum a melody to your chords. Once you have a melody to go with your chords, listen to what your hearing. The combination of chords and melody will provoke thoughts that meet the feeling of the music and then all you have to do is write about what the music is making you feel and once you get the first couple of lines going, use your imagination to ellaborate. This, in my opinion is far better than just scribbling on an empty pad.