The moment I entered the training centre, we had to constantly greet "Good Morning"and "Thank you" irregardless if it's your colleagues, friends, strangers, aunties or uncles. It's because in service industry, once passengers enter into the cabin, it's one of the aspects of introductory or an 'ice-breaker'.
When I worked for my first company, I remember having a boss who will come in to greet us
"Good Morning" and "How're you?". My colleagues and I would often give a silent reply and that wasn't the culture back in Malaysia unless you've had a good habit to greet, speak and communicate.
So i've learned to speak more, make eye contacts and not be afraid to just greet strangers.
Now, let's move on to having good manners. What I mean is opening doors for your colleagues, or anyone who is coming through. It's a good manners as we need to put customers first. There's a saying customers always come first.
It can be offering your meal, sharing your snacks, offering a bottle water, helping each other out to maintain our grooming, means looking out for each other.