This we believe, after 30 years of constant travel. Be courteous and respectful toward your bartender.
One thing I learned when I was traveling solo and dining in good restaurants is that it's usually easier (and more appreciated) to take a seat at the bar (I bring a book along)and order the menu from there. Be prepared to chat with your neighbors and the bartender. Trust me, they'll ask you about the book.
Step two, be sure to politely ask everybody's name. It goes along way. Pierino's MO is to order one (or maybe two) drinks along with food. Nurse your drink and get to know people. During my travels I've gone back to quality restaurant bars after a six month interval, and say, Mario up in Monterey remembers me and what wine I ordered and points up the best things on menu. Not because Mario is trying to "sell" them but because he personally likes them. The term "sous vide" seldom comes up.
I do this at home as well. Basically because I visit bars to eat and not to drink all afternoon. So, these people have become my friends and not my servants. Sometimes the chef will come out and chat with me for awhile.
Back to bar etiquette. Don't yell that "we want three Captain Morgans." You'll wait a full half hour for drinks. A nod is all you need, he or she knows you are there. And be sure to always say please and thank you. As in, "thank you, Heather." "And, yes, I will look at a menu thank you."
Now enjoy your food and your book.