WRITING SUMMARIES & CONCLUSIONS    

Strengthen your argument without repeating it.  
If the conclusion provides nothing new to the argument, only repetition, it will do nothing to further convince the reader of your point.  The argument can be strengthened by tying the arguments together, emphasizing a particular point, providing a strong piece of evidence, or putting the argument in perspective.  

Don't rewrite the introduction; revisit it instead.  
The conclusion should show how the argument has progressed within the body of the paper.  Revisiting the introduction is not necessary in every paper; but in a paper which traces a progression of arguments, it may be a good idea to tie those arguments together in the conclusion.   

Conclude with a strong example.  
End the paper with a final, convincing example which supports the main argument. 

Starting a new idea vs. expanding the old one.  
In general, it is a bad idea to start an entirely new idea in your conclusion.  Whereas adding another example strengthens the main argument, adding another  argument complicates it.  Although introducing new ideas may be harmful, discussing your argument "in terms that widen its significance" can be a very effective way to conclude a paper (Hefferman).   

The conclusion should grow from the body of the paper.  
Some conclusions appear as if they've been tacked on, as if the natural flow of the writing process was halted and a separate process took over.  Such abruptness should be avoided.  The conclusion is, after all, part of the same paper, and thus it should grow from the paper.   

Sometimes a conclusion is not necessary.  
If you've made all the points you can imagine making, stop writing.  Ending with your last point, if itís strong enough, can be enough to leave the reader with a clear idea of your argument.  

There really is no one right way.