When you refine something, you make it better. Whether it's sugar or an essay, refining it requires fixing its flaws.
You may think you created a masterpiece on the first try. But there's always room to refine. More than just working out the kinks, refining something means you're going to fine tune it, hone it to perfection, and make it more precise. In scientific terms, to refine something means to reduce it down to a pure state. At the dinner table, you can please grandma by refining your manners.