I usually go into a project by creating chords. After the chords are created, the melodies can start flowing. Basically, I write my melodies in the piano roll by using the scales of the chords as a foundation. It's hard to go wrong when you know all the notes are a part of the scale. Then from then on I create the percussion and move on from there.

I usually tend to structure my songs: "Part 1, Part 2, Part 1 (with counter melody or new portrayal), Part 2, Part 3 or Part 1 to the end."