It's almost always from reading an amazing book. Cheryl Strayed is a big one. Joyce Carol Oates. Lorrie Moore. Jeanette Winterson. David Sedaris. Toni Morrison. Zadie Smith. And reading poetry (Sandra Cisneros, Jane Miller, Rilke, Rumi) always makes me look at the world in a whole new way.
I'm on a self-improvement book kick and that's wildly motivating, as well.