Here are three most important aspects:

1. You must be prepared at all times, mentally, physically and spiritually (if you do have a religion or belief system). Just "Expect the unexpected." -- a well-known karate motto -- so you won't be caught unawares.

2. Once you decide to fight for your life (in a desperate situation where there is no way out) you must be fully committed, completely focused, be at the present moment. There are no rules, no referee. No "if's" and "but's". No, we are not even talking about robberies, muggings or carjacking etc. when the thug is only interested initially in your money or valuables. Quick, before he changes his mind, just open your wallet or purse, throw it to him (farther away from you, beyond his reach) and run away and yell. Or get out of the car asap and run against the traffic (so he can't quickly chase after you in the car). 

3. Run, run for dear Life! According to some USA statistics, 85% of the people who had faced a potentially lethal violent assault situation can survive simply by RUNNING LIKE HELL. Therefore, some running or sprinting capacity is essential for survival. For example, running 50 metres with all your might is your most important weapon of self-defence.

No material things in the whole wide world are more precious than your life. Unlike the cat, you have only one life to live. And this is not video gaming.