The best man offers the toasts during the reception, usually during the dinner, or just afterwards.
The toast may be very brief, “To Joseph and Jennifer, may they always be as happy as they are today”.
The groom who can propose a toast for the bride’s family may follow this first toast.
The groom’s father may follow and so on but the best man’s toast is adequate.
At a very formal wedding, the best man may make all the formal introductions of the different families and relatives and any out of town guests. He may also act as a master of ceremonies for the rest of the night if called for.
He also reads any telegrams that have been received.
Two different people may do the toast to the groom and bride. (Best man for the groom and maid/matron of honor or family member for the bride)
The bride and groom offer a toast of thanks to the guests for sharing their special day.