A strong thesis statement is one that can be backed by evidence from a reading, experiment, or research. This statement can be written in the form of a question or blanket statement within the first paragraph of your essay. The reader should be able to read this first paragraph and immediately know what the topic is and what your viewpoint or statement is.
Here is the build-up: Topic, Opinion/idea, Evidence.
When possible it is best to choose and topic and idea that you are passionate about or have an opposing viewpoint on. This makes writing easier and more enjoyable, and sometimes you can lean from an opposing viewpoint thesis.
Some examples include:
Good: Getting a sufficient amount of sleep every night is necessary to promote good physical and mental well-being.
Bad: You need 8 hours of sleep a night.
Opposing viewpoint examples: (if you believe that eating meat is unhealthy).
Good: A well-balanced diet, including meat, is essential to maintaining a healthy life.
Bad: Meat is good for you.