Hi! Your planned trip sounds exciting. Here are some tips for you.

Best Time to Visit:
The best time to visit these cities in Iran, including Kashan, Isfahan, Yazd, and Shiraz is during the spring (March to May) and fall (September to November). During these times, the temperatures are mild and the cities are full of vibrant colors.

Route and Accessibility:
You can start your journey from Tehran, the capital city of Iran. Tehran has international airport connections. From Tehran, you can take a bus or use a domestic flight to go to Kashan. After exploring Kashan, you can move to Isfahan which is about a 3-hour drive away. Then, take another 4-hour drive to reach Yazd. Finally, reaching Shiraz will take another 6-hour drive from Yazd. Every city is well-connected through public and private transport.

Accommodation and Booking:
Hotels and guesthouses are abundant in Kashan, Isfahan, Yazd, and Shiraz. It's advisable to book your accommodations in advance, especially for travel during peak seasons. Online booking platforms have a good selection of hotels to choose from, ranging from budget to luxury accommodations.

Clothing and Essentials:
Remember that Iran is an Islamic country, so modest clothing is essential. Women should wear a headscarf, and clothing should cover the arms and legs. Always carry a map, drinking water, and sunscreen. English is not commonly spoken outside of major tourist areas, so a translation app may be useful.

Health and Safety:
Travel insurance is recommended for travel in Iran. Carry a basic first-aid kit, follow hygiene practices to avoid issues with street food, and stay hydrated especially if traveling in summer. In case of an emergency, dial 110 for police.

Local Etiquette and Respect:
Iranians are known for their hospitality. Always accept if you are offered tea or a meal. It's polite to say 'No' at first as part of a tradition known as 'Taarof', but typically you are expected to accept the offer. Respect local customs and religious sites.