Clients booking 45 minutes and arriving expecting a full set — how do you handle it?

nail tech working from a home studio here. my biggest frustration is clients who book a 45-minute appointment and then show up expecting a full set or nail art they never mentioned. completely throws the whole day off and i never know how to handle it without seeming difficult. do you do it and overrun, turn it down on the day, or is there a way to prevent it at the booking stage?