1) Don’t spend all your time in Athens traveling to areas or sites out of the city, going back and forth, wasting time, and missing out on the countryside location.
2) Don’t “waste” a week in overrated Santorini & Mykonos, just because they are the trendy thing to do! Or, because they are the only islands your friends visited and know about!
3) Don’t drink Ouzo without ice and a snack.
4) Don’t eat “continental” food while in Greece! Eat … Greek! Don’t drink imported beers! Ask for the house wine!
5) Don’t queue & buy your Acropolis tickets at Acropolis. Buy the 30 EUR package ticket from another site (like the Temple of Zeus).
6) Don’t be afraid to socialize and be … cool.
7) Don’t be a tourist! Don’t be afraid to explore and do the non-touristy things.
8) Don’t eat dinner late; like the Greeks do.
9) Don’t do only the “ruins”. There is a lot more to do and see while in this country!
10) Don’t miss the hospitality and authenticity of Greece. Look for it!