Hello! That sounds like a fantastic journey. I'd be happy to provide some travel tips for Marrakesh, Fez, and Casablanca.

Best Time to Visit:
The best time to visit Marrakesh, Fez, and Casablanca in Morocco is during the spring (April to June) and autumn (September to November). These seasons offer the most pleasant temperatures.

Route and Accessibility:
Flights from various international cities land at Marrakech-Menara Airport in Marrakesh or Mohamed V International Airport in Casablanca. There are also train and bus services that connect these cities. Renting a car is common, though navigating in these cities can be a bit of a challenge due to heavy traffic and complex road system.

Accommodation and Booking:
These cities offer varied types of accommodations like Riads, guest houses, and luxurious hotels. It's wise to book accommodations in advance, especially during peak tourist seasons.

Clothing and Essentials:
Light, breathable clothing is advisable as temperatures can get high. A sunscreen, hat and sunglasses to protect against the sun are essentials. During winter months, carry warm clothing as temperatures can drop during evenings.

Health and Safety:
Tap water can be avoided. It's always best to stick to bottled water. Make sure to have your routine vaccinations up to date, and consult with your healthcare provider about recommended vaccines like Hepatitis A and Typhoid.

Local Etiquette and Respect:
Moroccans are traditionally a conservative people. Respect local customs and dress modestly. Try learning a few words in Arabic as a sign of respect. Always ask for permission before taking pictures of people.