Situational awareness is everything. Being alert to your surroundings. Preventing a gunfight is MUCH better than being in one. Although there is no duty to retreat in SC, the wise man avoids confrontation, if at all possible, with safety. Obviously, if walking away would put you in a chase situation or allow you to be cornered or moved into a less public/safe area, then retreat is not optional.
Low or no retaliation is the word. Protect yourself but don't continue the level of threat or escalate. Again, retreat or defuse, if possible, with safety. I know "swallowing your pride" and walking away is sometimes very hard, but it's better than swallowing lead. And, if you are at all responsible for the incident, you may be charged as well as the perp. Don't jump out of the boat and chase the sharks.
But, if you have to strike - strike hard.