Peak season is during the summer. Best time to visit to avoid crowds while still enjoying the beautiful weather would be late summer/ early Fall (September or October) and late Spring (March or April).

We visited during mid-September. Though there were still crowds I believe it was not as severe as it could have been peak summer and the weather was perfect!

We had a very seamless experience traveling between the islands with the high-speed ferries. I have heard stories of difficult passageways due to wind, but it does allow you to maximize time on the islands which was the most important for us. Also it allowed us to travel with snacks & wine. :)

I booked all of our transfers at once on ferryhopper.com. They make it so easy. Online reviews state that you do not need to worry about pre-booking. However, since travel in Greece has become substantially more popular, seats did sell out so booking in advance does not hurt.

Pack light! Cobblestone roads + ferry transfers = difficult with heavy luggage.

Greece is casual, leave your heels at home. You really only need: bathing suits, dresses/ short sleeve button-ups for going out, and sunscreen.

There is great shopping on the islands if you need to pick-up some souvenirs as well. :)

One thing to note, European airports are more strict regarding the 3-1-1 rule regarding liquids for carry-on items.

Keep in mind that a lot of shops and restaurants are closed on Sundays. However, most museums are open.

I would recommend 2-3 nights in Athens to be able to enjoy the extensive history and culture.

After a lot of research, most people also suggest staying in Athens at the end of the trip if exploring other Greek islands. Ferries can cancel/ become delayed, so it is best to have a few days to decompress in Athens prior to your international flight home.