Before writing your thesis statement, you should work to narrow your topic.
A Thesis Statement: Cats make great pets because they are fun to watch, independent, and low maintenance.
Why: This thesis gives specific main points to focus on, which are easy to discuss in detail.
Here are some of the thesis statement examples to help you make this task less problematic.
As you can see, there is no universal thesis statement formula as every type of a writing assignment requires a different approach.