First ask yourself a few questions:

• Would my reader appreciate a summary or find it unnecessary?
• Would a restatement of the thesis provide emphasis or dramatic effect? Or would it seem lazy and boring?
• Can I close with an overall reaction?
• What ideas related to my thesis do not appear in my introduction or body? Would closing with any of these ideas help my reader appreciate the significance of my topic or advance my purpose?
• Can I draw any conclusion from the points of my body paragraphs to help fulfill my purpose or to help my reader appreciate my view?

By answering these questions, you may discover a workable approach for your conclusion.  The final impression you leave with your reader will significantly influence your reader's reaction, so your conclusion must be carefully crafted.

Here are a few techniques to consider:

Leave the Reader with an Overall Reaction
With this approach, you will pull out some overriding impression, observation, or reaction  from the major points of the essay. You will leave the reader with a final sense of how you feel about the topic.

Summarize the Main Points of the Essay
This technique is straightforward. You will recap the major ideas presented in the essay. The caution here is that sometimes this can seem redundant. If you have written a short essay (anything less that 10 pages is short) with easily understood and easily remembered ideas, your reader does not need a summary and may grow annoyed at the unnecessary repetition. However, if your essay has many complex ideas, you reader might appreciate a summary at the end.

Introduce a Related Idea
Sometimes an effective conclusion can include an idea not appearing elsewhere in the essay. The caution here is that the idea must be clearly and closely related to the ideas that appear in the body of the essay, or the reader will be caught off guard by an idea that seems to pop up out of nowhere.

Make a Determination
Often, the ideas presented in the essay will lead to some significant point or determination. When this is the case, the conclusion can be used to state and explain that point.

Restate the Thesis or Another Portion of the Introduction
You can conclude an essay by repeating the thesis or another part of the introduction. There are a couple of cautions here. If you restate the thesis, you need to do so in a different way. Don't just copy and paste the same sentence you used in the introduction. The restatement is best used to achieve a dramatic effect that comes from repetition. A variation on this is if you start your introduction with some kind of a narrative, and you come back to that narrative in the conclusion. This can create an nice "bookend" effect that ties the essay together.

Combine Approaches
Your conclusion can combine two or more strategies. Any combination is possible!

A Few Things to Avoid
There are a number of common problems that you can avoid if you take the time to put your conclusion together carefully.

• Don't use cliche expressions such as "In conclusion" or "To summarize." Your essays are going to be short. It will be obvious that you are coming to the end. You don't need to make a big announcement. Your readers are not stupid--they can see this is the conclusion.

• Don't conclude with an apology or qualifying remark that undermines the readers' confidence in what they just read. You have just as much right as anyone to state your opinion, so don't apologize for what you have written.

• Don't make unfulfilled claims for your thesis. Chances are what you have written about does not have global significance, so don't imply that the world will come to an end if your opinions are not acted upon.

You should take as much care with the conclusion of your essay as with the introduction. Don't procrastinate to the point that you have to whip the conclusion off in the last 10 minutes before you have to turn the paper in. 

For more information on conclusions, check out these useful websites.

• Information Power: Writing Effective Conclusions

• Effective Conclusions

• Hamilton Writing Center: Conclusions

• Writing Effective Conclusions

• Strategies for Writing a Conclusion

• Strategies for Effective Conclusions