1. Reading that challenges my preconceptions, and inspires me to begin thinking about a topic in a new way. This is especially helpful as I am working within a tradition, and tradition is a tricky, dialectical thing to work with. It lays down restraints that must be tassled with, and it cannot be entirely free-form shaped, because you are working with material that is dear to others, and thus you must work within a field of tensions and (hopefully) flexible guidelines. But challenging reading material can inspire one to test the edges of that flexibility and work to restore it where it has given way to rigidity.
2. Reading penetrating, imaginative material on the lore of Germania obviously inspires me to write.
3. Important works of fiction based in careful study of the lore are also tremendously helpful. Here as a prototype we might cite Tolkien, whose scholarship on the Northern ways was impeccable, but in addition whose intuitive insight into the shape of the lore, even as he leapt into pure fiction, was astounding, as he puts forth shapes that match lore-facts he couldn't have known at the time. And, as I mentioned, Donna Gillespie's work.