The following email was recently sent to me by a writer friend.
At one point in this email, I mistakenly used your instead of you’re. This iPhone is doing me no good whatsoever, though I still love it so. Please forgive. I know YOU will notice it. Just ignore it. I just need you to know that I know.
For those of you convinced that your "got degrees in English" friends are judging your (not "you're") grammar, this is meant to reassure you. Sure, certain rules were so pounded into our heads that we do notice. Can't help it! Still, these kinds of inadvertent typos happen to even the most fastidious writer-types, so remembering our own oops moments can help to keep us humble. And hopefully not too (not "two" or "to") judgey.
I got a kick out of her note because although I can't remember for certain ever having sent such, it's the kind of thing I would consider sending!
And for those of you who still struggle with usage (it took me a long one to sort this one out, too,) here's a handy Wiki write-up that might help.