About a year ago, I acquired a large potted Kaffir Lime tree as part of the purchase of a home in Hawai'i. I've just transplanted it from the pot to the ground sparking my curiosity about the tree again. After searching around to find out what it was and what it was used for, I bought my first wok and took up preparing Thai curries and other dishes. So, in my dwindling ignorance of the uses for my Kaffir Lime tree, my one pressing question right now is: How do you choose which leaves to pick from the plant for use in flavoring the dishes? ... The larger, older, tougher leaves, or the smaller, younger, more tender leaves? Does it make any difference at all?