Primum non nocere
This Latin phrase means “first, do no harm”. It's a foundational principle in medical ethics.
And personally I apply it to ethics more broadly.
It's simply this: as long as you don't cause other people to suffer in a way they haven't deserved, you are a good person in my book. And I'm a good person in this way too, you can count on it.
I do think it is our ethical obligation to be considerate, especially to nice people whom we like. This has implications for behavior in public. Some ways to potentially be inconsiderate and violate this principle:
Hopefully you can sense the common pattern and recognize where else this applies.
Nothing else is strictly required. But I find it necessary to specifically call out charity. Because thanks to certain religions, many people believe charity to be everyone's obligation. I reject that notion and I stand my ground. In fact, demanding charity is inconsiderate, and violates the do no harm principle.