Whenever you take control of a meeting, you acknowledge the person who yielded control to you. This can be done by a simple “thank you.”
If you are the person yielding control, you do not sit till you have been acknowledged.
For example: the Toastmaster, Teresa introduces the prepared speaker, James.
Teresa waits at the lectern till James arrives. She shakes James’ hand and wishes him well.
Teresa remains standing off to the side till James acknowledges her by saying “thank you Madam Toastmaster”. Only then does Teresa sit.
Barrie Toastmasters Club 