To make sure your espresso service goes smoothly you also need to check that:
spoons and stirrers are available and clean
service trays are available and clean
you have enough takeaway cups and lids
you have enough paper serviettes
you have enough cups, saucers, glasses and bowls available. These should be:
clean and stain free (if stained they should be soaked and scrubbed)
free of damage (if chipped or cracked, throw them away)
pre-heated (by storing them on the espresso machine and/or pre-heating with hot water before use).