Well a lot of this is up in the air to both the artist and the genre you are composing in. I personally premeditate and chart out all of my music first. However, as the melody starts to form in my head I always come up with lyrics ( this also helps to see if the melody can fit w/ in the harmonization and it makes it easier to remember the melody if its set to words. )

Hope this helps.

-Kyle Hicks ( Kole )
-http://www.myspace.com/kolemusic