Here's an ideal itinerary for 5 days in Mykonos:

Day 1: Arrival and Beach Day

• Arrive in Mykonos and check into your hotel
• Head to one of the island's beautiful beaches, such as Paradise Beach or Super Paradise Beach
• Spend the day soaking up the sun, swimming in the crystal-clear waters, and enjoying beachside cocktails and snacks
• In the evening, head to Little Venice to watch the sunset and enjoy dinner at one of the many waterfront restaurants

Day 2: Explore Mykonos Town

• Start the day with a traditional Greek breakfast at a local cafe
• Explore the charming streets of Mykonos Town, with its white-washed buildings and colorful doors and shutters
• Visit the iconic windmills and take in the stunning views of the Aegean Sea
• Stop by the Panagia Paraportiani church, one of the most photographed churches in Greece
• Enjoy lunch at a local taverna, and then spend the afternoon shopping for souvenirs and handmade crafts
• In the evening, head to the Mykonos Folklore Museum to learn about the island's rich history and culture, and then enjoy dinner at a traditional Greek restaurant

Day 3: Delos Island Excursion

• Take a ferry to the nearby island of Delos, one of the most important archaeological sites in Greece
• Explore the ancient ruins, including the Temple of Apollo, the Terrace of the Lions, and the House of Dionysus
• Learn about the island's fascinating history and mythology from a knowledgeable guide
• Return to Mykonos in the late afternoon and enjoy dinner at a seaside restaurant

Day 4: Day Trip to Tinos Island

• Take a ferry to the nearby island of Tinos, known for its beautiful beaches and traditional villages
• Visit the famous Church of Panagia Evangelistria, one of the most important pilgrimage sites in Greece
• Explore the charming village of Pyrgos, known for its marble craftsmen and traditional architecture
• Enjoy lunch at a local taverna, and then spend the afternoon relaxing on one of Tinos' secluded beaches
• Return to Mykonos in the evening and enjoy dinner at a local restaurant

Day 5: Sailing and Sunset Cruise

• Spend the day sailing around the island on a private yacht or catamaran
• Stop at secluded coves and beaches for swimming and snorkeling
• Enjoy a delicious lunch on board, prepared by your private chef
• In the evening, watch the sunset over the Aegean Sea and enjoy a glass of champagne
• Return to Mykonos and enjoy a farewell dinner at a local restaurant

I hope this itinerary helps you plan your trip to Mykonos!