How important can it be if you want to win a potential partner or customer? It must really be the right greeting! Let's compare: a greeting in Chinese business practice and a greeting in European cultures described above.
Chinese:
The handshake is the most popular form of greeting in China, contrary to the popular belief that the Chinese greet each other by bowing with their palms together at chest level.
The bow is still only used in some rural areas of China and during family gatherings, especially during major holidays such as the Chinese New Year. In the bow, it is customary to cover one hand over the other at chest level, moving the folded hands up and down.
The person in a higher position or older usually takes the initiative in the handshake process.
The handshake should not be excessively long or very quick, but kept simple and light, not too vigorous.
Have an unobtrusive eye contact throughout the meeting and try to appear friendly and attentive.
Hugging, kissing, patting the shoulder or back, and touching in general are not allowed in this culture.
If you are introduced to a group of Chinese people they might start applauding while greeting. Do the same in response, and it will be seen as a polite step on your part.
Iran is a country with very long and incredibly rich cultural traditions. It's also a multi-ethnic state and so the style and manner of communication may differ depending on which ethnicity you are dealing with. Let's see what is important to know about their cultural features.
In general, Iranians' speech is not straightforward. On the contrary, they often use figurative language, without naming things by their proper names. The most important aim of communication is not to offend or embarrass the interlocutor, so the latent subtext is significant and can be expressed through non-verbal communication - gestures, facial expressions, intonation, as well as through separate words understood only by the speakers of this culture.
In Iranian society, there is an unconditional focus on human relationships, and it is important to be tactful, avoid strong opinions, and generally not express thoughts too linearly. If the speaker does need to express a negative answer, it will appear rather evasive in Iran.
In conversation, avoid asking general questions that require a "yes" or (especially) "no" answer, especially if your question could be interpreted as a request. Your partner will probably agree to do what he is being asked, but it will be something he would not want to do. Instead of an outright refusal, he might politely but evasively agree, or say, "I'll think about it," "I'll see what I can do."
Such hidden meanings are well understood in Iranian society. However, foreigners will have to take the time to understand them and learn to respond to them adequately. So be careful and discreet when speaking with your partner.