I think I've come up with a method for making my parents use my actual name.
Ask them not to.
The last time my dad "accidentally" called me by the wrong name and tried to apologise, I simply told him to use my old name. I said that I want my friends to use my real name - like they all have done for 2+ years - but I don't want him to use it.
That was the first time he ever seemed genuinely taken aback by my response to him misnaming me. I'm curious to see if transphobia or reverse psychology will win out in the long run.