That totally varies on so many different things. I'll hopefully be able to convey a bunch of writing thoughts and ideas on the upcoming DVDs. But for a quick reply, some scales that I use are major/minor, harmonic minor, half/whole tone, whole tone, some exotic scales that I don't know the official name for, sometimes combine parts of scales like a cross between blues and harmonic minor, etc... For chords and clusters I use just about anything and everything, but I really dig when there is a m2 or diminished 5th interval. That could come from or lead to just about anything, so there are so many possibilities. In other words, it's kinda difficult to answer your question. Sorry about that...
Ron