Keep your eyes open and watch your footing.  You might encounter a challenging idea.

Trees seem to feature quite heavily in my work – trees which look like gothic architecture, gothic architecture which looks like trees, tree roots, trees belonging to dryads. I like using trees and other plants for their symbolic value, or the significance they have in a story, as well as for the way they look. I'd already done this in Oberon in Blue and Willow Dryad when it occurred to me that the Bible is full of significant and symbolic trees.