When thinking about Middle Eastern etiquette, it is important to remember that the Middle East is incredibly diverse, and it hosts communities which have wildly different rules of etiquette. Although there are a few etiquette tips which hold true throughout the Middle East, it is a good idea to solicit advice from locals before visiting a region to ensure that you do not cause offense by accident. Many guidebooks for various regions of the Middle East also have etiquette sections.
Many rules of Middle Eastern etiquette are simply commonsense, and if you happen to have grown up in a very traditional family, your manners are probably good enough to travel in the Middle East. Many Middle Eastern cultures place a heavy emphasis on mutual trust, respect, and friendship, so by being polite and deferential, you can often succeed in social situations. For example, in many Middle Eastern communities, older people expect a very high level of respect; you should always stand when older people are in the room, unless you have been told to sit, and you should greet older people first.
When interacting with people in the Middle East, the rules vary, depending on where you are. In many Muslim communities, for example, it is considered extremely rude to enter a room without greeting everyone. Although non-Muslims are not expected to say salaam aleikum (peace be with you), although it is polite, but they should most certainly say hello every time they enter a room and respond to such greetings. Displays of affection between people of the opposite sex are generally frowned upon in Middle Eastern etiquette, although people of the same sex often hold hands or kiss each other's cheeks, without the connotations carried by these actions in the West.
You may also want to be aware that many Middle Eastern communities have a strong honor ethic, considering someone's word as bond. Therefore, you should never orally promise something you cannot deliver. Many visitors to the Middle East also struggle with Middle Eastern body language; personal space bubbles are much smaller in the Middle East, and gestures which would be used to convey anger or upset are not used in the same way in the Middle East. Therefore, it can help to listen to someone's tone of voice, and to be careful about your own body language.
Many Middle Easterners also place a heavy emphasis on hospitality, especially in the Arab community. It is considered impolite to refuse hospitality, whether it takes the form of a cup of Turkish coffee, or a lavish meal. When you accept hospitality, be polite and gracious, and follow the behavior of other people in the room if you are not sure about how to act. As a general rule, it is considered impolite to show the soles of your feet or shoes under Middle Eastern etiquette, even if you are sitting to eat, and at many Middle Eastern tables, food is presented in a central dish which everyone eats from. In this situation, guests use wedges of bread as scoops in the central dish, and it is important in Muslim communities to avoid using your left hand to touch food or other people, as the left hand is reserved for personal hygiene.
When you are offered food, as a guest you will be offered the choicest parts of the meal, including delicacies which may seem unusual or foreign to you. Keep in mind that refusal of such delicacies is offensive under Middle Eastern etiquette. Meals and meetings in the Middle East can also seem confusing to people from the West, since people often travel in and out and interrupt proceedings. This is because many Middle Easterners mix business and personal relationships, creating a strong network of friends and associates which can be relied upon. It is best to go with the flow in these situations, and try to avoid seeming pushy or impatient.
Finally, a note about haggling. Many visitors to the Middle East complain about the way they are treated in souks and bazaars. Hagging or bargaining is a very important part of Middle Eastern culture, and it is viewed as offensive to refrain from engaging in it. Rather than being put off by it, visitors should join in the fun, making preposterous offers and questioning the merchant's claims. Transactions in the Middle East often take time, and may be interrupted by breaks for coffee, tea, and snacks. By haggling, you will earn the respect of the merchant, creating a much better relationship which could be quite useful later on.