Women and/or solo travelers, how do you keep yourself safe?

I am a frequent traveler, originally from Germany but I spend a lot of time in the Netherlands and the United States.

I find that even though the Netherlands feels much safer than the U.S. for me as a woman who travels alone, there are still areas where I feel unsafe. Amsterdam for example feels like a mixed bag where I feel welcomed and safe in some places and vulnerable and unsafe in others. Nothing compared to in places like Detroit on the U.S though haha

How do you keep yourself safe when traveling both within and outside the Netherlands?