Copied and pasted from Dean Spade at the Sylvia Rivera Law Project:
People often wonder how to be polite when it comes to problems of misidentifying another person’s pronoun. Here are some general tips:
1. If you make a mistake, correct yourself. Going on as if it did not happen is actually less respectful than making the correction. This also saves the person who was misidentified from having to correct an incorrect pronoun assumption that has now been planted in the minds of any other participants in the conversation who heard the mistake.
2. If someone else makes a mistake, correct them. It is polite to provide a correction, whether or not the person whose pronoun as misused is present, in order to avoid future mistakes and in order to correct the mistaken assumption that might now have been planted in the minds of any other participants in the conversation who heard the mistake.
3. If you aren’t sure of a person’s pronoun, ask. One way to do this is by sharing your own. “I use masculine pronouns. I want to make sure to address you correctly, how do you like to be addressed?” This may seem like a strange thing to do but a person who often experiences being addressed incorrectly may see it as a sign of respect that you are interested in getting it right.
4. When facilitating a group discussion, ask people to identify their pronouns when they go around and do introductions. This will allow everyone in the room the chance to self-identify and to get each others’ pronouns right the first time. It will also reduce the burden on anyone whose pronoun is often misidentified and may help them access the discussion more easily because they do not have to fear an embarrassing mistake.