Striking with knuckles or kife hand also has effect. Grab with your fingers and squeeze. Bring knee up into groin. Any blow to this area will hurt the attacker. This is one of the best vital points for an inexperienced person to apply.
Side kicks work best.
Be very wary using any kicks above the knee in a street fight. You will be susceptible to a take down if your leg is too high. Low front kick to kneecap can break joint or momentarily put attacker off balance allowing a finger jab to the eyeballs or a testicle strike. A good hard kick to the front of the shin bone will cause great pain to the attacker. Most effective if you are wearing shoes with strong toe area.