Handmade Greek sandals are sold in Plaka and Monastiraki. Ask where they were made, and try both feet before buying.
Olive oil & honey
Thyme honey, olive oil and mountain tea travel well. Pack liquids in checked luggage.
Ask who made a piece and where. Check materials and shipping. Bargain politely only where invited; respect fixed prices in boutiques and artisan shops. In the flea market, gentle bargaining is normal; shops and boutiques keep fixed prices.