When you say yes, let it mean yes. When you agree to a time, show up at said time. When you hold a door open, wait those extra 10 seconds for the person that’s jogging to get to you. When you order your coffee, ask the barista how their morning has been. When a waiter clears your table, stack plates and utensils in a logical way and say ’thank you.’ Tip well if the service was good. Drop food off when your friends are sick, and maybe even when they aren’t.
It doesn’t take a lot to be a good decent human. It’s not about massive shifts in character, it’s small daily decisions that build to a change over time.