Scenario: It's night, and a man is walking home. He sees ahead there is a woman going in the opposite direction as him. Knowing not to stop or approach her, but his presence makes her nervous. What would help further in this scenario if anything?
A thing that should be emphasized, is that humans learn how to behave in different situations by practice. If a given passing-a-woman instance suggests that you made her nervous, while regrettable, isn't the end of the world. Try different things. With practice, you can find what works for you, and will gradually get better at "acting normal" or presenting in the manner that seems to produce the desired result.