Who has encountered car rentals in Greece - what should I consider?

I am planning a trip to Greece and want to rent a car to drive freely around the islands and cities. But I heard that there are some nuances with documents and insurance. Who has recently rented a car, tell me what is the best thing to pay attention to?

I recently rented a car in Greece, and I can say that it is better to look carefully at the conditions beforehand. Sometimes the price in the advertisement seems great, but then there are extra charges for insurance, gasoline or return in another place. To avoid surprises, it is better to choose a proven site. Here, for example, there are car rentals in Greece at https://getrentacar.com/en-US/greece