Example:

Using Examples in Your Argument (Darling et al)
Giving Examples and Explanations (Sentence Sense)
Using Specific Language (Sentence Sense)

Even though you may be making a fine point, you must resist the impulse to make the same point over and over again. 

Use an outline to structure the different points in your argument. Make the paragraph your basic unit: one key point per paragraph. Once you've made your point, move on to another paragraph.

Pruning Redundancy (Darling et al)

Sometimes the conclusions that you draw are not warranted by the evidence you have collected to support your argument.  If your interpretation is a simple one, hesitate and discuss it with someone before writing your paper.  Most books read in English classes are called classics because they are subtle, not simple.  Unless your point is that an issue indeed is black and white, it's usually a good idea to hedge your claims with words and phrases like generally, sometimes, often, to some extent, in some ways, etc.  Instead of saying, "the evidence shows or proves that," consider saying something like, "the evidence suggests or supports that."

For example, the next-to-last sentence hedges in three ways:

Also, consider phrasing your arguments in relative terms:

A weak essay will draw self-evident conclusions based on the evidence. Instead, one should explore the complexity and ambiguity of the moral dilemmas that we encounter in great literature.

For instance, drawing the conclusion that Hamlet's indecision can be explained by simple cowardice does not do justice to the real complexity of his character. Furthermore, Hamlet displays physical courage at various moments in the action. On the ramparts, when he encounters the ghost of his father, Hamlet brandishes his rapier and threatens to 'make a ghost' of his friend Horatio who is trying to prevent him from following the vision to another part of the castle. Cowardice cannot explain Hamlet's behavior at this moment.

Example:

Also, consider phrasing your arguments in relative terms:

Many times students will make excellent points in the body of an argument, but unless the points are specifically related to the essay's thesis, then they are not topical and should be edited out of the final draft. 

For instance, in an essay about Macbeth's character, it would be a mistake to focus on why Lady Macbeth goes mad unless you can tie that line of action directly to Macbeth's own journey into madness. 

This is one of the most frequent comments inserted to student compositions. Frequently, in early drafts of a paper, a student will touch on very interesting ideas but not develop them into key parts of his or her argument. For many students writing a rough draft is an essential stage of the writing process. They will brainstorm excellent insights into the text, but, unfortunately, they do not take the time to revise their paragraph's topic sentence or even the essay's thesis to develop this line of reasoning. 

For instance, students writing about Hamlet will find interesting routes into the mystery of Hamlet's motivation, but they won't take the time to fully explore their insight. Many students will state that Hamlet is much more angry with his mother Gertrude than he is with his uncle Claudius, but they will not take the time to explore the significance of this idea.

At other times, students will make the same point over and over again in a single paragraph. The best essay writer will take the time to substantiate the key point with good examples, but he or she will make the point in the fewest words possible.