Think about things you don't know how to do. :)

Disclaimer: I've never been mugged, and only noticed a few possible attempted muggings. All this comes from a few years of martial arts training roughly halfway between RBSD and TMA.

If you can't avoid walking past someone who makes you feel uncomfortable, walk quickly and over-emphasize the motion of walking: Swinging your arms shoulder-high automatically defends against many attacks.

The "interview" phase of an attack takes different forms. Between young males in a bar, it'll be an escalation through verbal, postural, and physical aggression. In a profit-driven crime, it will be subtler:

If someone's on an intercept course for you, move perpendicular to their path and see if they track you. If they're getting within 20 feet, direct them to one side or the other by pointing, or put up a hand in the "stop" gesture. Depending on the circumstances, either tracking or ignoring your "stay away" gesture, alone, provides a strong enough likelihood ratio to justify fighting or fleeing. Don't turn your body away or close your eyes; that may turn away the wrath of an alpha, but it'll get you eaten by a predator.

another edit:

Anytime anybody has a Monday or Wednesday evening free in Tampa Bay, get in touch. My instructor's a kinesthetic genius and loves working defense in the liminal space between the intention to attack and the first punch.

Certainly some relevant information in these recent posts on learned blankness (comments are a goldmine) and building small skills in the right order.

I've experienced a notable increase in acuity of focus, multi-tasking, list-making and avoiding unnecessary mental hiccups through a few things:

• practicing mental math on the 3-4 digit arithmetic practice on Khan Academy (which interestingly enough, while I did not consciously define it, taught me to approach learning in a rather similar manner to that described in the two LW posts linked above)

• sites like Lumosity, Cognitive Fun, and especially (Brain Workshop's)[http://brainworkshop.sourceforge.net] Dual N-Back Game and another game which I have lost the link to involving visually tracking multiple objects (gems in this game's case) - hopefully someone will come along with the link!

• reading papers (articles, lectures, etc) as a group, out loud, slowly, and answering questions as they arise, allowing for as much as several hours over coffee in a quiet room to read even something that's only a handful of pages long. It helps to encourage deep discussion but to have someone around to keep the conversation relevant, as it tends to stray too far off course.

• going over a Bach piece as a group with someone who understands, even if vaguely, music theory and counterpoint and following the voices and how they interrelate.

I suppose that's what I've got to contribute for now. Possibly more later. YMMV, this is largely anecdotal aside from the flash games.