Port will traditionally be served after pudding. If the dinner is informal, or at a restaurant no ritual will be involved. At a formal dinner you are not to take even a sip before the Loyal Toast.
When a part decanter is placed on the table for you to help yourself, always pour and then pass on to the left. If the port goes by without you pouring, do not ask for the port to be past back, send your glass after the port decanter.
In the military various messes have different customs including banging the decanter on the table before passing it. In some messes the decanter touches the table or does not touch the table however there is no standing Army custom.
