Now-a-day, when I have less-than-nice thoughts about someone, it helps me to think about how that person is someone's mother, or daughter, or father, or husband, or son, or friend. They are beloved to anonymous someones, and thus they become instantly more lovable to me.
Perhaps, I can overlook their quirks or ignore certain remarks. Maybe I'll be strong enough not to wish someone's loved one harm or to go fuck someone's loved oneself. Because I certainly would be hurt/pissed if someone else was mean to a loved one of mine.
(I'm getting soft in my old age, eh?)