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

"In Grecia it is considered polite to greet people with a handshake and a warm greeting whenever possible. Therefore, it is important to be mindful to avoid any disrespectful or rude behavior. While speaking to local people, address them in a respectful manner and avoid making comments about their customs, culture, or language. It is wise to dress modestly and refrain from being overly loud or boisterous in public places. Additionally, one should respect religious institutions and avoid taking photographs unless given permission to do so," mentioned another expat when asked about moving to Grecia, Costa Rica, Costa Rica.