Get the lowdown on Alonissos, Paxos, Ithaca, Kea and Lefkas as Lisa James picks some little-known islands in the Aegean
If your clients have already holidayed in some of Greece's major islands, there are still dozens of other, much smaller options to put to them.
We asked the experts to suggest some of their favourite lesser-known islands.
One of the less-visited Sporades islands, off mainland Greece's east coast, Alonissos is a tranquil, green and fertile island, perfect for walking and suited to nature-loving couples, whose idea of nightlife is sitting in a taverna admiring the sunset on the harbour front of Patitiri.
Alonissos's surrounding waters are a designated marine park and visitors can take daily boat trips to nearby islands.
Getting there: Flight to Skiathos, followed by a 75-minute ferry transfer.
Operator verdict: Ionian Island Holidays agency sales manager Bernadette Askouni said: "It's a quiet island where you can get away from it all. The perfect place for nature lovers and those who enjoy walking surrounded by natural beauty. The island is especially interesting for bird lovers and anyone interested in diving, as the waters are spectacularly crystal clear."
Sample product: Seven nights at the self-catering Karnagio Beach Villa, a traditional two-bedroom property with private pool, costs £620 per person, based on four people sharing. Price includes flights, transfers, seven days' car hire and welcome hamper. (020 8459 0777, Ionian Island Holidays agent site)
One of the smallest of the Ionian islands off the western coast of mainland Greece is Paxos. It is defined by small, pretty villages, a thickly wooded landscape and white pebble coves.
It's a paradise for walking, especially in the spring when the wild flowers come out. The population is just 2,500, and Lakka, Loggos and Gaios are the main waterfront towns. Gaios is the capital and it has an attractvive square and plenty of cafes and bars. Loggos is the prettiest, with 30 old houses clustered around the water.
Getting there: Flight to Corfu, followed by ferry transfer.
Operator verdict: Sunvil Greece director Dudley der Parthog said: "Those wishing to avoid the busier resort areas and experience the 'real Greece', would be well advised to look at Paxos. It remains relatively peaceful, and offers a more romantic and authentic experience of Greek island life that is perhaps more suitable for the mature market."
Sample product: Sunvil has one week at the self-catering Mermaid Cottage near Loggos waterfront, from £725 per person in August, including flights and transfers by private boat. (020 8758 4758, Sunvil agents site)
While Ithaca is everywhere in Greek legend, it is relatively unknown to tourists. It is believed to be the home of Odysseus and visitors can discover the legendary places mentioned in Homer's The Odyssey, which charts the hero's story. It's a good option for people interested in history, archaeology and Greek mythology.
The appeal is also in Ithaca's secluded beaches, tiny fishing villages and inland hamlets, as well as ancient monasteries.
Ithaca is very unspoilt, peaceful and laid back, and its olive groves are the mainstay of the island's economy.
Getting there: Flight to Kefalonia, followed by ferry.
Operator verdict: Greek Islands Club director David Watrous said: "Ithaca will appeal to those looking for a relaxed and friendly atmosphere, clear waters, and an escape from built-up resorts."
Sample product: Greek Islands Club offers seven nights at the self-catering House of Phoebe, a traditional island house, from £768 per person, including flights and transfers by private ferry. (020 8232 9780)
One of the Cyclades islands, this is the least touristy, as it has no package holiday market. Sunisle is the only UK operator to feature Kea. Visitors are unlikely to see another non-Greek tourist as the majority of people who visit are Athenians on a weekend break.
Accommodation ranges from stylish boutique hotels to rustic houses, and is based mainly to the north where there are several great beaches, particularly Gialiskari and Otzias bay.
The nightlife is surprisingly sophisticated, with a few popular bars in Korissia and Vourkari. The capital Ioulis has a maze of little cobbled streets and there also many archaeological sites to visit in Kea such as the Temple of Apollo at Karthia or the ruins at Agios Marina.
Getting there: Flight to Athens, followed by a one-hour ferry transfer from Lavrion, a 40-minute drive from Athens airport.
Operator verdict: Sunisle marketing director Nick Darby said: "Kea takes you back to the Greece of 30 years ago. The post lady also delivers the bread on her round. Visitors are treated as special and welcomed by the locals. Prices are also lower to reflect the local economy rather than tourism."
Lefkas, off the west coast of mainland Greece, is a beautiful, fertile island with some superb beaches, an imposing mountainous interior with views of vineyards, olive groves and cotton fields.
It is a prime windsurfing and kite-surfing resort. The gentle morning breezes are ideal for beginners, and the strong afternoon gusts are suitable for experienced surfers. Lessons can be booked. There are some bustling tourist resorts with beachside activities and late-night bars, but visitors will also find walking trails into mountain villages, where rural life continues much as it has done for generations.
Getting there: Flight to Preveza on the mainland, followed by a road transfer over a bridge or through a tunnel that connects Lefkas to mainland Greece.
Operator verdict: Cosmos product manager Erica Collins said: "Lefkas is thoroughly unspoilt. Its spectacular sand and pebble beaches are simply stunning and there's a real unhurried atmosphere about the whole island.
"If your customers want to do more than unwind, there is plenty to do in the bustling beachfront village of Nidri where there's a good range of shops, restaurants and bars. Alternatively, suggest an excursion or day trip to one of the outlying islands. The island's capital, Lefkas Town, also has plenty of nightlife."
Sample product: Seven nights' self-catering at the two-star Studios Borsalino in Nidri costs £179 per person, based on three sharing a studio. (0871 423 8518)
Ios lies between Naxos and Santorini in the Cyclades and is renowned for being the burial place of Homer, 'the poet of poets'.
Its package holiday history is unusual. It used to be renowned as a party destination to rival Faliraki or Ayia Napa - so much so, that it was shunned by holidaymakers looking for a more sedate experience.
Now the authorities have worked hard to change people's perception of Ios. It is now much tamer and attracts a more upmarket type of holidaymaker.
The capital, Mylopotas, is still lively, but the island's hidden gems are to the north and west, where the lifestyle is much quieter, with timeless villages and secluded beaches.
Getting there: Flight to Santorini, then a 90-minute ferry ride. Catamarans and hydrofoils also operate, which are quicker.
Operator verdict: Olympic Holidays commercial director Photis Lambrianides said: "Ios is a very small island that appeals to clients who want to get away from the big resorts to somewhere more quiet, quaint and off the beaten track.
There are no big hotels, just small, family-run places, giving it a secluded, romantic feel. Its position far south means it has a very hot climate."
Sample product: Seven nights' bed and breakfast at the Marcos Beach Hotel on Ios costs £335 per person, including flights from Stansted and transfers to the island. (0800 093 3322, Olympic Holidays agent site)