The first steps into any Italian restaurant begin with courtesy. Greet staff with Buongiorno (good morning / hello, formal) during the day or Buonasera (good evening) after about 5 p.m. Sprinkle in per favore (please) and end with grazie (thank you). If someone thanks you, reply with prego (you're welcome / go ahead). To politely get a staff member's attention, say Mi scusi or simply Scusi! — never snap your fingers or call out cameriere loudly.
Once seated, you'll want to manage the ordering flow. To request a table, say Un tavolo per due, per favore (a table for two, please). To see the menu, ask Possiamo avere il menu? (can we have the menu?). If you'd like a recommendation, try Cosa consiglia? (what do you recommend?). When the server asks if you're ready to order with Volete ordinare? (would you like to order?), you can respond with the useful phrase Vorrei… (I would like…) or Prendo… (I'll have…). Asking Avete…? (do you have…?) is a great way to check on specific dishes.
During the meal, a few phrases cover most needs. To request something, use Mi può portare…? (can you bring me…?), as in Mi può portare il sale? (can you bring me the salt?). If you want more, ask Posso avere ancora un po' di pane? (can I have a bit more bread?) or Un altro bicchiere di vino, per favore (another glass of wine, please). To request water, say Vorrei una bottiglia d'acqua (I would like a bottle of water). The phrases Va bene (OK / all right) and Subito (right away — often said by servers) are useful acknowledgments. Once you've decided, Lo prendo (I'll take it) seals the deal. If you've changed your mind, Lasciamo perdere (let's forget it / never mind) lets you gracefully back out.
At the end of a meal, two phrases add warmth. Buon appetito! (enjoy your meal!) is the classic toast servers or fellow diners offer before eating. Salute! (cheers! / bless you!) is used when toasting with drinks — or said when someone sneezes.