• Include an introduction that is interesting and that sets up the essay -- either by setting the scene or introducing key issues and concepts.
• Be sure you have a plan or outline.
• Be sure your essay is well organized -- that ideas that belong together stay together.
• Organize your work carefully - by time, by order of importance, by logical progression.
• Be sure your essay's main sections have strong topic sentences.
• Use transitions to help the reader follow your logic (therefore), to mark contrasts (on the other hand), similarity (similarly), sequence (next), example (for instance).
• Include a conclusion that sums up your main points and that illustrates the significance and meaning of your points.

Argumentation and Analysis

• Keep your purpose and audience in mind.
• For exploratory essays, be sure your introduction  introduces the main ideas in question clearly.
• Avoid vague generalizations; they are hard to support and defend. 
• Give plenty of details. Show me, don't tell me.
• Give plenty of specific support -- examples.
• Develop your ideas.  Flesh them out. Comment extensively.

Style

• Do not announce your opinion or soap-box. Simply state your case. The reader will gather how you feel about a certain issue from the tone, the focus of the argument, the claim itself.
• Avoid passive voice sentences (is/am/are/was/were or any form of /to be/)
• Pick a tense (usually the present tense) and stick with it, unless you are referring to the historical past tense.
• Chose your words carefully.