Women should wear non-transparent clothes and covering all their bodies except for the hands and face. They should also wear a head scarf or cap to cover their hair. They can use any color and there is no compulsion. It’s OK to wear flip-flops and sandals.

There is no national religious dress code for men. Jean and pants are more common and also shirt or T-shirt. It's recommended for men do not wear short trousers in public place but it's fine in natural and rural place.

Both carrying and drinking alcohol as well as taking drugs is prohibited on the territory of Iran. Instead you can try local and non-alcoholic drinks which are domestic with special taste.

It's good to know that all restaurants and cafes are closed during daylight in Ramadan month. However, some of them work secretly to serve the travelers who can skip fasting.
in addition pork or bacon is an illegal meat in Iran but you can use seafood, poultry and any other red meats.

Nowadays Iran protect its safety although it's located at the center of Middle East. Security system created a safe environment for foreign tourists. Mass media intensified this security. There are codified rules for tourism and tourists and the visitors have special rights.
There is a little points for driving care at the streets.
Usually it's common to have a tour guide in every new country for a foreign visitor he/she could informs you the best instructions.

There are some vegetarian restaurants in main cities of Iran and also there are vegetarian meal on the menu of other restaurants. As well some of the Iranian foods have a right recipes for vegetarians.