I fall short sometimes on this. We all do, I expect. Not the part about receiving grace. I do that quite naturally. LOL! But thinking the best of others, knowing that in general everyone is doing their best on any given day, is something that it takes practice to be mindful of.
I'm also pretty good at not taking things personally. In fact, anytime someone has something nasty to say to me or about me, I automatically assume that they're having a bad day and that I had nothing to do with it. Sometimes I'm right, sometimes I'm not. But I usually never know which. And that's OK. So, in a way, I am very freely gifting grace by making that assumption. Some might say that I am just engaging in aloof snobbery. That's also OK.
Where I get a little crazed is when someone has something nasty to say about or to someone that I love. For some reason, in that moment I can't make that same assumption. I feel so utterly defensive when it's about someone else and there is no excuse, or bad day, or "doing their best" that makes it OK. I will fight you.
Even as sweet, forgiving, full of grace, and unconditionally loving as Levi is, he will still bark like hell at the lawn mowing guys on Wednesdays to defend my honor. But, he would warm up to them pretty quickly given the chance. And maybe that's what people need, a few chances to get it right.