Make a specific point or assertion about your topic in your thesis statement. Avoid asking questions in your thesis statement. Instead, answer the main question that your paper is proposing. Also, avoid opinions, and make your thesis as factual as possible. Ensure that your premise is based on information that you can support with specific, reputable research and evidence.
Stay away from sweeping claims and hasty generalizations. For example, do not make assumptions or conclusions based on an inadequate sample of people or information. Do not use stereotypes to generalize. Create a thesis that is specific and focused. A good way to do this is to have a claim that you can support with several different studies or groups of reliable research. Research your claim thoroughly before you begin writing your thesis sentence.
Do not use an either/or approach. For example, do not say that a person needs to join the gym or risks being over weight. Clearly there are other ways to lose weight, so claiming that joining a gym is the only way creates a weak argument. Instead, you can say something like joining a gym helps many people stay inspired to lose weight.
Avoid weak analogies. Many thesis statements will rely on an analogy between two ideas, so make sure these ideas are actually comparable. Weak analogies are sometimes used to compare the effects of alcohol to those of illegal drugs. Here is an example of a weak argument that could be seen as a fallacy: Because both alcohol and illegal drugs are used recreationally, drugs should be legal if alcohol is.
Avoid cause-and-effect arguments. For example, just because one event happens before another event does not mean the first event caused the second. Making this assumption is a type of fallacy. A more complex version of this fallacy is called the slippery slope. This type of logical fallacy occurs when someone tries to argue that one thing will lead to another and then to another, etc.