Final answer:
To acknowledge a new customer's presence, be friendly, smile, make eye contact, and greet them with a polite greeting.
Step-by-step explanation:
In order to acknowledge a new customer's presence, it is important to be friendly and welcoming. Smile and make eye contact, and greet them with a polite greeting such as 'Hello' or 'Good morning'. You can also use their name if it is known to you. Showing warmth and helpfulness towards the new customer will leave a positive impression.