Use an appropriate greeting to make your customer feel welcome. Customers nearly always have a choice of which businesses and organisations they use, they didn’t have to pick ours.
Start positively with a warm, sincere welcome; but don’t overdo it! “Good Morning” and “Welcome” are all simple introductions and you can follow up with “How can I help”, “Is there anything you would like me to focus on specifically today?” or some other appropriate comment to indicate that you are there and happy to help.
Never complain to a customer about your organisation, your day, how busy you are, the management, your colleagues or anything else that may lead the customer to develop negative feelings.