The best way to travel to Santorini is via air. There are several flights every day from Athens International Airport to Santorini. The most popular destinations include London, New York, Paris, Amsterdam, Frankfurt, Milan, Zurich and Berlin.
You can easily book cheap tickets online. However, you might want to check out some extra charges such as baggage fees and fuel surcharges.
There are many ways to reach the airport. If you plan to fly into Athens, there are public buses and taxis waiting outside the arrivals hall. Taxis are expensive, especially during peak hours. Buses are cheaper but less convenient.
If you prefer to go by car, you can rent one from local companies. There are plenty of options available.
Alternatively, you could just buy a ticket and catch a ferry from Piraeus port to Santorini. You can find ferries departing daily from Piraeus to Santorini. Ferries depart from Piraeus every hour and take about 3 hours to arrive in Santorini. There is also an option of a fast ferry or a slow ferry, depending on how much time you have.