In many parts of India, people eat using banana leaves as plates. Oftentimes, each food is arranged differently and placed in a particular corner or part of the leaf, and the type/taste of each item seems to influence this placement (sweets go in one section, rice in another, etc.) I've also heard of some 'rules' about what direction the leaf should be facing and other 'rules' about how the leaf should be washed.
What I'm wondering is, are there actually any rules set out in the canon? And if so, what are they? How should we prepare the leaf and how should we arrange the food?