Ive been using pine needles this year, because theyre all over the ground by the hives, and Ive been short on time, BUT:
Last year, when I was a bit more ambitious, I sat down one rainy day, and cut cardboard strips as wide as my smoker is deep, and burlap the same, and rolled them together (alternating) into little canister shapes that slid right in the smoker. I liked them far better than pine needles, but havent had time to make a bunch up yet.