I don't see my family often, so even 19 months later they slip up. I'm rarely with them in public, so i haven't made a huge deal out of it. They address things to my right name (Dad from the beginning, Mom just starting to) and have changed legal stuff (wills) to reflect my new name and 'son'.
They are in their 70s now and I did point out to my mom that if she kept calling me she, that people would think she was losing it (since I don't look remotely F any more!). That helped.
One guy I know, who was also passing 100%, had his dad introduce him to someone by saying "I see you met my daughter!" All he could do was an eye roll and made a gesture to imply his dad must have been drinking, to which the person smiled like they understood. Later he told his dad that outing him could get him killed in the wrong situation, which helped.
Funny thing happened to me last week when I went to my primary doc for the first time since transitioning. I've always liked her, and so since I need a good physical and tests and such prior to my surgery, I figure now is the time to re-establish my relationship with her. I had to make the appt under my F name, as the doc is not taking new patients, which I did over the phone. I walked in, stated my last name, and that I had an appt. She pulls my file, which is clearly F, and doesn't so much as do a double take. No shock, surprise, nothing. All she said, in a very matter of fact voice, was that oh it's been a while since you've been here. To which I replied yes. But then the nurse didn't wait for the updated info and called F name. I waited a minute (still filling out the form) to respond. And once inside said my name is M name now.
Not sure if they have other trans patients or not; don't think so after talking to my doc who kept saying wow over and over, LOL. But she was fine with stuff.
Jay