The Listen To Other Music Technique
I don't know about other people, but trying to write lyrics whilst listening to other music - music you actually enjoy - can help inspire me with new lyric ideas and such.
It can also help a little with finding new rhythms and song structures. Then, if you get a final or draft piece of lyric, you can even change the melodies and timing etc...
As long as you don't steal the other person's or band's lyrics, of course.