My usual routine:
Firstly I make the music. After the whole song is ready I listen to it to find out what kind of mood it has. Then I write lyrics that feel right for the song. The last thing I do I add in all the guitar solos. The reason I'm leaving the solo playing the last is that I want the solos to tell their own story. I can only hear how the solo should sound after everything else is done. This method works me the best.