1) Go through your paper and on a separate piece of paper write one sentence that states the main point of each paragraph. Make sure the sentence doesn't describe the paragraph but sums up the content of the paragraph.

Bad: "This paragraph is about the dangers of water in Beowulf"
Good: "Water is dangerous in Beowulf because it is a place where evil creatures dwell"

(Hint: you may want to leave out the introduction and conclusion for the moment and just deal with the body of the paper).

2) After you have a list of sentences, read them as if they were a paragraph. Do they make sense in that order? If not you need to think about moving things around a bit. Do some sentences seem to express similar ideas? That may be a sign that those paragraphs should be grouped together. Are there sentences that repeat the same idea? You might think about combining the ideas in those paragraphs or cutting one of diem. Shift your sentences around until you have a paragraph that seems to make sense. You should be able to explain the logical relationship between each of the ideas in the paragraph.

3) Cut and Paste until you have a logical progression of paragraphs.

4) Now you can check and make sure that you r paragraphs are coherent. Go through each paragraph and look to see if you directly say the ideas you wrote in the sentence on your list. If not, make sure you say them somewhere in that paragraph (most likely these ideas can serve as topic sentences).

5) Make sure that every sentence in your paragraph addresses that main idea. If it doesn't it shouldn't be there.

6) Make sure your thesis matches the rest of your paper. If you added it to that paragraph you wrote in step 1 would it make sense? If not, you may need to revise your thesis.