Nothing. I don't use anything to defend myself, and I've never been attacked. Now, to be perfectly clear, I'm not saying it never happens, and I personally might deflect a lot of would be attackers because I give off a vibe like I'm looking for a fight. On the other hand, I used to walk around by myself in shady parts of town during the wee hours of the morning on a nightly basis, and I never even got so much as a vague threat. I feel that, if stranger attacks on women were as common as so many people seem to believe, I at least would've had one challenger. Not so. I had exactly zero.

Again, not to minimize anyone's experience in case I'm abnormal in this regard, but I feel like this "need for self defense" is kinda overblown, and perhaps even deliberately overblown in an attempt to sell "defense classes" to people who would otherwise have no interest in martial arts or weird "defense" weapons that can be hidden in purses and bras.