I fell in love with Greece when my wife and I eloped in Santorini in June 2016. Santorini was the final island we visited after Paros and Crete. The next summer, we returned to the Aegean to visit three new islands: Hydra, Folegandros, and Milos. In 2018 we returned for another anniversary trip, this time visiting two new islands, Rhodes and Symi. Now it's tradition. We're going back for the fourth year in a row, to explore the Ionian island of Corfu.
Each of these trips has been 9-10 days in length. To plan them, I scoured guidebooks, maps, and blogs. I even deciphered descriptions of the islands in poetry and literature. Here are some tips for anyone considering a trip to Greece.
1. Stick to one island group
Just because islands look close to each other on a map, does not mean they are easy to get to. It's best to choose one family of islands and stick to it. Otherwise you'll waste all your time on ferries.
2. Fly directly to/from the islands.
Many islands have airports. You don't necessary have to stop in Athens to get to them, or to get home. I always try to get to the islands in no more than two flights. And I live in Seattle. So I usually fly to a major hub in Europe (Frankfurt, London, Paris, Dublin) and then find connecting flights directly to/from a given island.
A few examples:
Heading home after our wedding in Santorini, we flew nonstop to Frankfurt on Aegean Air, then nonstop from Frankfurt to Seattle on Lufthansa.
Last summer, to get to Greece, we flew Norwegian to London Gatwick, then direct from London to Rhodes on British Airways.
This summer, we're going to Corfu; we found a nonstop flight from Seattle to Dublin on Aer Lingus, and another direct flight on Aer Lingus from Dublin to Corfu.
3. Order islands strategically.
Try to arrange islands so that you start and finish on islands with airports. That will at least give you the option to avoid an extra flight (to Athens). Check out Olympic Air and Aegean Air for the shorter connecting flights in and out of Greece.
Something very important to remember: Ferries don't run every day. Some ferry routes run only twice per week, even in peak season. This means that when ordering islands on your itinerary you're at the mercy of the ferry schedule. It's best to start with a rough idea of how you want to arrange islands, but not to lock anything down (or book accommodation) until you're sure the ferries and flights align.
4. Use ferries sparingly.
I personally love the ferries in Greece. You get a different perspective of the islands when you approach ports from the water. But they can take a while. Since there are no direct flights between the islands (they all route you back to Athens first), ferries make sense (most of the time) for transport between islands. Just be realistic about how much time the ferry ride will eat up--usually a full day when you factor in rental car pick-ups/returns, embarking/disembarking, and inevitable delays.