Choose an essay topic that you feel confident writing about, even if it would entail thorough research. Ask your professor for her feedback once you have chosen a topic. Some classes may require you to submit a proposal and have the professor approve the topic.
Brainstorm your topic. Write down possible points that you can write about. Make sure to list at least three points. For example, if your topic is about why it we should become more energy-conscious, you can list global warming, depletion of natural resources, soaring fuel costs and pollution health risks as possible points.
Write down a few concepts and statements for each point. You may find that some points are easier to write about than others. Do not worry, because this is fine. Circle the three points that have the most information. These three points are what you will use for your thesis.
Come up with a thesis statement. This is essentially what your essay will be about in one sentence. For example: "It is necessary for the world to become more energy-conscious because of global warming, the depletion of natural resources and health risks caused from pollution" would be a solid thesis statement. You always want to introduce the topic, then insert the three points after "because."
Experiment with how the thesis looks and works. Ask for your professor's opinion and if he has a sample thesis for you to look at. You may find that one point lacks more material than the others and you want to replace it with another one. Do not get discouraged; it may take several attempts before you are satisfied with your thesis.