I have a few that have already been mentioned, eating small candies in pairs by color or flavour, food not touching, etc...
I eat my pizza crust first. , then I take small bites of the part near the crust to make it even (fold it in half to do that part). After that, I turn it around and eat it from the small sized back, still keeping it folded. I only at Pizza Hut pizza with a fork and knife.
I not only eat chips/fries in size order, smallest to largest, but they have to be eaten in pairs. I have broken fries in half to make equal amounts before.