What I've found helps me the most is to call to mind that I'm only human. I'm going to make mistakes. I try to proceed thru life with caution about what I say and do, but I'm still going to fall short. When I do, I say I'm sorry to whoever I've wronged, and then forgive myself by reminding myself that I'm simply human. Then I try to take actions to not make the same mistake again. And when I find myself really bothered by something someone else has done, I try to remember that they are only human as well. Probably trying to do the best they can with what they've been given. IDK if this helps at all, but it's a good go-to for me.