The first lesson Donatello will teach you is to show strength while negotiating a truce in an effort to avoid the use of force. Rather than show excessive aggression, it is best to let your foes know that you are not afraid but also that you are not looking for a fight.
If the enemy continues to advance, your next step is to ready your weapon and assume an attack stance. Again, do not engage them as there still may be time to resolve things peacefully. However it is important to show that you are prepared to defend yourself.
If all attempts to avoid a fight have failed, now is the time to attack. Defend yourself with honor and protect the innocent people around you from harm.
After the battle, recover and celebrate with the preferred nourishment for ninja turtles... pizza! A good day's work deserves a good slice of hot cheese and pepperoni.