What's your garden planting plan?

I just picked up some bare roots from Home Depot (zone 9b). I've only had one peony before - love them, they are so gorgeous. But given the short lived nature of the blooms and that the plant dies down in winter, what sort of planting layout do you work off of? Do you plant them behind other stuff so you don't have a lot of emptiness and bare ground? What are your favorite companion plants?