How do I know that the reader infers correctly what I want to say?
Do not leave it to the reader to infer what you mean! You should better begin writing with an assumption that your reader would be unknowledgeable, inattentive, and bored to make sense of your writing. Therefore, you should make the process of “making sense” as simple as possible.
To do this, your position should be stated explicitly in your thesis statement and restated again in the conclusion. You should also make sure you give a lead in into every supporting point and a concluding sentence explaining how what you have just written supports your point.