Hello! That sounds like an amazing trip to Morocco. Here are some travel tips to help you plan your visit to Marrakeach, Ouarzazate, and Merzouga.

Best Time to Visit:
The best time to visit these places is during Spring (mid-March to May) and Autumn (September to November) when the weather is mild and comfortable.

Route and Accessibility:
You can easily start your tour from Marrakech. There are daily flights from major cities to Marrakech. From Marrakech, take a bus or pre-arranged taxi to Ouarzazate. Finally, you can reach Merzouga by bus from Ouarzazate, or you could opt for an organized tour.

Accommodation and Booking:
There's a range of accommodation options available from luxury hotels to budget guesthouses and desert camps. It's best to book early, especially during peak seasons. Many places also offer online booking or you can book through a travel agency.

Clothing and Essentials:
Consider light, breathable clothing for the day and warmer layers for cooler evenings, particularly in the desert. A hat, sunblock, sunglasses, and a water bottle are recommended due to the arid conditions. Don't forget your camera for the breathtaking views!

Health and Safety:
Travel insurance is recommended. Ensure you're updated on routine vaccines. Though the tap water is generally safe to drink, bottled water is advised for sensitive stomachs. Be careful with heat exhaustion and always keep hydrated.

Local Etiquette and Respect:
Remember to dress modestly respecting the local Islamic culture. Always ask for permission before photographing locals. Arabic is the official language, but many people speak French and English too.