Even I am planning for a trip to Greece and have a rough itinerary. Just sharing my plan in case it helps. Also sharing 2 itineraries that I found really helpful and will have more details on what to do in each location. Day 1-2 - Athens (Fly-in) Day 3-5 - Mykonos Day 6-8 - Santorini Day 9 - Athens (Fly-out)