First of all, you need good manners to become a real gentleman.
If you do not have this, go find a guide about getting some manners, but otherwise you're free to continue with this guide.

There are a lot of rules for you to follow, if you want to become a gentleman:

The true gentleman does NEVER run, even if he's in danger.
It looks stupid, and should not be done under ANY conditions.

He does not curse, hurt, nor disrespect his fellow survivors, unless they hurt or disrespects him.
Note that even if someone hurts or disrespects you, you shouldn't curse. People will doubt that you're a true gentleman. Instead, fight him back with words, for example you can discreminate his way of acting like an ignorant primate. He might start crying, but don't say sorry, he deserved it.

He respects what he kills.
Don't EVER kill just for fun. Only kill other living beings if you need their materials,
and remember, if there is another solution, don't kill. Killing another being, is the last thing the true gentleman would like to do.

He doesn't get his hands dirty.
Do not wear any kind of weapon.
weapons are made for killing, and killing is uncivilized.
But remember, the rock is not a weapon. It's a tool.

He ALWAYS stays classy.
The gentleman is a womans man, so only wear cloth or leather clothing.
Don't even think about wearing kevlar. They run and kill in the military, so you don't wanna look like one of them.

He does not raid innocent survivors.
It's their stuff, and it belongs to them, so don't ever raid innocent survivers.
You may raid the hated people called bandits, because they probably got their stuff from killing.
If you do so, you shall not take anything, just open all the door ways, and remove the sleeping bags. Nature will take care of the rest.