A formal encounter with The Queen will be intricately organised and choreographed, so you should wait to be presented rather than initiate an introduction. Men should bow from the head only, and women should make a small curtsey. Neither movement should be prolonged or exaggerated. It is acceptable but less usual to shake hands.
Address The Queen as ‘Your Majesty’ and subsequently as ‘Ma’am’ (to rhyme with ‘jam’). As far as conversation is concerned, you may be briefed in advance as to how much time is available. However, allow yourself to be guided during the audience itself. Relax and behave as naturally as possible. If you are introducing another person to The Queen, simply state the name of the person as follows:
“May I present John Smith, Your Majesty?” When conversing with The Queen, substitue ‘Your Majesty’ for ‘you’.
When writing to The Queen, address your letter ‘Madam’ or ‘May it please Your Majesty’ and close with ‘I have the honour to remain, Madam, Your Majesty’s humble and obedient servant’. In the body of the letter, substitute ‘Your Majesty’ for ‘you’ and Your Majesty’s’ for ‘your’.
The envelope should be addressed to ‘Her Majesty The Queen’.”