I first think about the way I'd like my new song to sound, and then I try to create it. When the music is ready, I make a vocal melody and I write the lyrics. Finally, I record it, and then I work arranging and mixing everything. This takes me between 3 and 7 hours per song.
This is the way I create most of my songs, but sometimes I come up with an idea when I have no time to work on it, so if that happens I try to record the melody with my cellphone, that way when I'm at home I can keep working on it.