Im not sure if this will make you kinder but I find many many people skip very easy oportunities to make a small improvement in the world. These things are miniscule but they are things everyone can do all the time. Grab a cart from the lot if you pass one by that is not in a choral as you go to the store. Pick up litter that you pass by and toss or recycle it. I live in a condo complex and if my neighbor have packages that are easy enough to carry I bring them up and put it near their door and they actually now do the same for me. Not only a great convenience for us both but a great little human interaction for us both that makes us closer neighbors. Hold a door for someone, offer a seat on a train. Just keep in mind if you have an oportunity to do something that is scarcly and inconvenience for you but makes the world a better place. I would add smile when you see people. Be nice whenever you can and even return rudeness or such with strangers with kindness. You don’t have to deal with their stuff every day so its easier to be pleasant and move on.