Bow and curtsy, for the Queen, even if you are royal.
Bow and curtsy have always been a part of the royal protocol. We have seen the general public bowing or showing curtsy in front of the Queen of England, Queen Elizabeth. But it is uncommon or not a widely known fact that the royal family members are also obligated to bow and show curtsy for the Queen.
As for the men of the royal family, they are required to wear a neck bow. The Royals were shown to follow these protocols before the Queen, but we are not sure if they are required to follow these etiquettes and protocols in private or is just customary for public appearances.