What cultural faux pas should I try to avoid making in Thessaloniki?

"When visiting Thessaloniki, it's important to respect the local customs and traditions to avoid any cultural faux pas. Avoid discussing sensitive topics such as politics, religion, and the country's economic situation, as these can lead to heated debates. Greeks are very proud of their culture and history, so refrain from making negative comments about them. When visiting churches or monasteries, dress modestly and remember to remove your hat. Women may also be required to cover their heads. In Greece, it's considered rude to wave with an open hand, as this gesture is used as an insult. Instead, wave with your palm closed. Avoid using the "OK" hand gesture (forming a circle with your thumb and index finger), as it is considered offensive in Greece. Punctuality is not highly valued in Greek culture, so don't be surprised if people are late for appointments or social gatherings. However, as a visitor, try to be on time. Tipping is customary in Greece, so remember to leave a small tip in restaurants, cafes, and taxis. Finally, Greeks are known for their hospitality, so if you're invited to someone's home, it's polite to bring a small gift for the host," remarked another expat in Thessaloniki, Greece.