One of the simplest ways to defend yourself is to use your car keys. You are more likely to injure your hands if you use your fingernails.
If someone is coming at you from the front, a groyne kick may be enough to paralyse your attacker, allowing you to flee.
This move can injure the nose or throat. To execute, get as much as possible in front of your attacker.
If your attacker is close and you don't have enough momentum to throw a powerful punch or kick, use your elbows.
Depending on how you're standing when you're attacked, you might be in a better position for elbow strike variations.
You should use this move when the attacker is approaching from behind. Concentrate on getting low and making space for yourself to be free.
If your attacker approaches you from behind and traps your arms (similar to a bear hug, but you won't be able to move as freely),
Your first instinct should be to avoid being choked if the attacker wraps their arm around your head from the side.