Formulate the thesis as a question. What is the central argument or point of view expressed by the essay? The thesis statement lets the reader know why the essay topic is important, how it is addressed by the essay, and what your solution to the problem is.
Present the thesis statement as one main idea. A thesis statement that contains more than one central idea is confusing to the reader. A well-written essay should focus on one central idea or topic. Related ideas and topics, that support the main idea, can be developed during the course of the essay.
Make the statement clear and specific. Ambiguous thesis statements leave the reader uncertain or unsure about the topic or purpose of the essay. Specific statements tell the reader exactly how the essay addresses a particular topic. A general rule of thumb to follow is for an essay is to pick a controversial topic. Presenting a clear and well-defined solution or point of view makes the reader anxious to read the essay to either agree or disagree with it.
Test the thesis statement on several colleagues or friends. Ask the colleague or friend to read only the thesis statement and then ask them for their impressions about the essay. If the thesis is strong, unambiguous and specific they should have a good idea about the specific details and arguments of the essay.