How to write a slogan saying that if there are any leftovers in the cafeteria, you will be charged accordingly?

I have seen an example before. It said that a cafeteria put up a sign saying that there would be a fine for leftover food in order to prevent customers from leaving food. Later, fewer people went to the restaurant to eat. Someone gave the restaurant an idea to increase the price by ten yuan, and give a 10 yuan reward if there was no leftover rice. After the implementation of this plan, the restaurant's business improved again. Whether you are a businessman or a consumer, you will consider your own interests before buying or selling. The customer is God. We hope that you will consider the consumer's perspective when formulating a plan. Hope this helps.