I would say that one of the most basic elements behind a conclusion is to ensure that it effectively covers all of the information presented thus far in the paper and summarizes it in an effective manner. I think that individual instructors have separate beliefs on what needs to be included in a conclusion. Having said this, I believe that a good conclusion should include some discussion of the implications of the thesis statement. Perhaps this could involve some level of discussion of how the thesis statement and its findings presented in the paper has meaning or relevancy to the topic of studying. An artful conclusion seeks to broaden and widen discussion instead of merely ending the work.
While it seems a mute point to say that the purpose of writing is to communicate clearly and effectively, sometimes writers lose sight of the very important method of doing this:
- Tell your readers what you are going to tell them
- Tell it to them and illustrate/prove it, using details to explain or develop the support
- The, tell them what you just told them
This last point is what a conslusion does. It rewords what have been stated and supported. Then, it extends this idea with a quote, or a "clincher," an originally expressed thought that emphasizes the main point or extends it.
Another way the conclusion is completed is in the following:
- stress the importance of the thesis statement
- give the essay a sense of completeness
- leave a final impression on the reader [this is the "clincher"]
See the enotes links below for help with the construction of an essay.
If you re-post your question and give us additional information, it will be easier to answer you more specifically. In general, however, there are a lot of theories about how to conclude an essay. A very basic plan is to restate your thesis statement from the opening paragraph. At your level, this should be done in a skillful way, however. If you simply restate what you have already written, it will be simplistic. Your ending also will depend heavily on the type of essay you are writing. If the essay is informative, for example, then you could go the "restate the thesis" route. However, if it is humorous essay, you have more freedom to be creative. In this case, the ending should have a strong impact - leave the reader smiling or laughing at the end. If the essay is more philosophical in nature, it can be effective to end with a dynamite quote that is germane to your topic. Also, some very persuasive essays can be ended strongly with rhetorical questions.
I could go on and on. As you see, there are so many possibilities. That is why we need more information in order to help you.
Essays may be of various kinds, each kind having its own requirements in respect of form and style. It would have been better if you had mentioned your topic/thesis.
In any case, the Conclusion to an essay must be a neat and careful tying up of all the threads of your discussion in the main body of your writing. Summarise the whole course point by point, keep referring to and emphasising your thesis statement, focus on the inference arrived at and the relevance of that inference to further studies on the subject. Remember that a good Conclusion should be more than merely aggregative. It must be stimulating and critical.