1. Do not use your fingers for anything. Always use tongs/serving spoons. It makes me cringe when I see someone pick up a roll with their hands.
2. Only take what you can eat. I always overeat at buffets, but it helps a lot to just take less to begin with so you're not stuffed and no food goes to waste.
3. Move efficiently in the line, especially if it's crowded.
4. Don't bring a used plate up to the line again.
5. Thank everyone, as we always say!
Keep minding your manners!