When are you most vulnerable? Many people go through their daily lives oblivious to the dangerous situations they may be putting themselves in. For example, if you own a business, do you bring money in and out of your store on the same day every week or month? Or maybe you work nights in the city and you walk alone to your car at the same time every night? Often people attribute violent attacks to random acts, but in reality further questioning after the fact reveals several indicators that could have served as a warning. One of these factors often is the predictability of the victim.
Soldiers and diplomats receive training that teaches them to vary their patterns of activity, travel routes, timing, etc. to make it difficult for those who mean them harm. However, sometimes that's not practical and a pattern of activity still exists. In those cases, they take special precautions knowing that they face a higher level of risk when conducting predictable routines. What special precautions can you take during the predictable and vulnerable parts of your day? Perhaps it's as simple as showing that you are aware, and not walking around staring at the sidewalk. Most criminals prefer the easy, oblivious targets. Don't be one! Think from the perspective of an attacker. When would you attack yourself? During those moments consider taking some extra precautions yourself.
Awareness is probably the most important self-defense skill, and fortunately, one that is easy to learn and anyone can use.