Quick Tip:
It is customary to add a honorary suffix to the last name of a customer or someone who you do not know well. Xiānshēng（先生）is for men and Nǚshì（女士）is for women.
Basic greeting:
早上好 (Zǎoshang hǎo) 纳撒尼尔 先生/女士 - Good morning, Mr./Ms. Nathaniel