Italians love guests, just like most peoples in the Mediterranean. And guest is whoever is not a regular and is invited. Hence, you will be guests as you enter Italy.
Now, guests are supposed to know how to behave, and if you won't know the rules, you won't be a guest for long. So watch yourself and make sure you avoid at least these easily spotted pitfalls.
First, avoid tourist traps. No matter how hungry you are, no matter how uncomfortable it seems to order in Italian - avoid the restaurant in front of the Vatican that shouts on large billboards: "English Spoken". If you do, you'll deserve the lousy food and the exhorbitant prices. Rule of thumb: if you see Italians, hear Italian, then you are allowed to go in.
Next: there are no free refills. Everything is paid, so don't get surprised at the bill with four sodas for two. Stunningly enough, water is always free (except if bottled) and in small trattorie, the wine in the carafe actually gets refilled for free. And it's not bad, either!
Speaking of beverages: no coffee with meals. Even the dreadful americano is to be taken without the context of eating. Meals are for water, wine and sodas strictly. Iced tea would be an odd choice, but if you can cope with the loads of sugar, the waiter will cope with your selection.
Check prices first. It may look like a second-class trattoria, but it may be the talk of the town right now. So check the prices before you get shocked. Especially when you are in a tourist area.
We touched on this one already before: Don't expect big breakfast. Cappuccino will have to do most of the time. And if you think you can't do without more food, then choose your headquarters in a hotel equipped with an American breakfast. You'll find the usuals in Italy, too: Hilton, Holiday Inn, etc.
The best food is hidden. Italians watch their restaurants and eateries constantly, and for some reason, after a place gets famous, the quality suddenly drops. If you have friends that are locals, or if you made new friends: let them show you the places that are in right now. The rest will be less than satisfactory.Next: Let's talk about art