Q: What's the secret behind nice passing chords?
A: the secret is the same for any kind of chords, which is simply to learn all the notes/chords in all the songs you like, and eventually all the relevant powers you could ever need will come to you in a sort of natural assimilative osmosis. side note is that you can't get this from other people's transcriptions, because everyone transcribes differently, and you will only get the actual powers if you transcribe it in the way that you heard it