Even if chords are simple, they should rub. They should have dissonances in them. I've always used a lot of alternate bass lines, suspensions, widely spaced voicings. Dfferent textures to get very warm chords. Sometimes you're setting up strange chords by placing a chord in front of it that's going to set it off like a diamond in a gold band. It's not just finding interesting chords, it's how you sequence them, like stringing together pearls on a string. ... Interesting chords will compel interesting melodies. It's very hard to write a boring melody to an interesting chord sequence.