We've all been there. You present your last supporting argument, but you don't know what you can write that will end your paper without leaving the reader "hanging".
You know what a good conclusion looks like, so how do you reverse-engineer that? Let's start with a few of the "nuts and bolts". The purpose of your conclusion is two-fold: (a) it ends your paper; and (b) it reminds the reader of your thesis and the major points you've proven or explained. Most people get stuck on part (b). It can be simple, though, once you plan it out.
Before you begin drafting that conclusion, take a close look at your introduction. You will find that the same ideas in that beginning paragraph can be incorporated in the content of your paper's final paragraph. Ask yourself: How do I re-word my thesis statement from the introduction? What are 2-3 of the major objectives in my paper? How effectively was I able to explain and support my thesis in the body paragraphs? The answers to these questions will guide you further as you plot out your conclusion. Use the conclusion to remind readers of your main points and show them that you've effectively explained why your thesis is a good one.
Don't get discouraged if you need to edit and retool your conclusion upon your first reading of it. After all, writing is re-writing. It’s also good to get the perspective of an outside reader, because they are distanced from your work and can view it with less bias than you could. A good conclusion will satisfy the reader in that they will understand your true intent, the purpose of your arguments, and the viability of your approach to the topic.