In short, walk with purpose. Or walk angry. Fine, use whatever emotion you want, just don’t look awkward or clumsy (i.e. drunk).
Take the picture above for example. Just look at that guy! That handsome, sturdy, angry guy. He’s walking fast, he’s clearly in a bad mood and, judging by his clothes, he hardly has any money anyway. Muggability rating: zero.
Researchers came to this conclusion by showing videos of different people walking to violent criminals and movement experts (dancers, actors) and asking them who seemed most vulnerable.
The predictable targets (women, old people) were often singled out, but even some young men were given high muggability ratings because they appeared to be subtly less sure-footed.
Now we can’t walk fast and angry everywhere we go for the rest of our lives, but apparently adjusting one’s gait could discourage unwanted attention under the right circumstances.
Also, crazy eyes. Nothing short of automatic weapons shrinks genitals faster than crazy eyes.