How to be invited to dinner more than once

So you've been asked to come to a nice dinner, and boy, are you excited! It's been such a long time since you were last invited to one of these things. What was it... Thanksgiving, six years ago? The food was so fantastic you were looking forward to the next year, but for some reason your invitation just seems to have kept falling through the cracks. You're not really sure why, but...

OK, let's just cut to the chase. Your boorish behavior at that Thanksgiving dinner six years ago pretty much guarantees you'll never be invited to any meal in that particular household again. Not only did you overstay your welcome and eat far more than your share, your table manners were a step away from a hog slopping. And never once did you thank your host for the meal. No one would blame them if, once you finally departed, your hosts sighed, "Well, that one's never darkening our doorstep again."

Want to increase your chances of being invited to eat at the same household more than once? Read on.

NOTE: This is only a quick start guide to table manners. If you want the real deal, I highly recommend The Little Book of Etiquette by Dorothea Johnson as a reference that will cover 95% of most formal dining concerns. (You may need a more protocol-oriented reference book if you've been invited to dine with the Queen; otherwise, you're good.)

1. I started off detailing how to take a bath for a good reason.  Make sure you and your clothing are clean, presentable and appropriate for the occasion. (If you're not sure of the appropriate dress for dinner, ask your host.)
2. At the door, say hello. Smile.  Introduce yourself by name if necessary. Look your host in the eye (if this makes you uncomfortable, look at the bridge of your host's nose instead) and say, "Thanks so much for inviting me."
3. Bring a small gift for your host. It can be a nice bottle of wine (if your host drinks), a bouquet of flowers in a vase, seasonal fruit in a basket, or something to share for dessert. Whatever it happens to be, TAKE OFF THE PRICE TAGS BEFORE YOU GET THERE. It's also a good idea to offer the gift after you've come inside; don't just thrust it across the threshold at your host. You don't have to do this, but consider that they also didn't have to invite you. A wisely-chosen small gift definitely starts things out on the right note.
4. If this isn't a super-formal dinner and your host is still putting the finishing touches on the food when you arrive, offer to help with preparations. (After you've washed your hands, of course.)
5. Be seated at the table only when you are invited to do so. Otherwise you look like a sugared-up six-year-old who can't wait to eat his weight in mashed potatoes. Easy there, Calvin.
6. Your napkin goes in your lap. Don't use anything else to wipe your hands or face. (Especially not the tablecloth; that trick went out of fashion before Shakespeare's time.) If you need to blow your nose, excuse yourself and go to the restroom to do it; no one wants to see or hear your snot going 90 MPH.
7. A general rule that will rarely steer you wrong: if you're not sure what to do (which fork is the right one to use? how do I eat this artichoke?), watch your host and follow his or her lead.
8. In an American family-style dinner party, guests usually pass the food to be served around the table. Always stay fully seated to pass serving dishes; if something's too far away to reach, ask someone closer to pass it to you. Do not reach over someone else's plate to get an item, and never eat directly from a serving dish, for Pete's sake. Don't start to eat until everyone has been served; if you're not sure when to start eating, watch your host. When you take food from a serving dish, think about other guests who have not yet been served. If you're not sure what a reasonable serving is, watch your host. It is sometimes permissible to take a second serving after everyone has had a first; again, watch your host.
9. The rule of thumb about flatware: start on the outside and work your way in for each course. And don't clutch your cutlery like you're going after Dracula. You should hold your knife and fork similar to the way you hold a pencil. The knife should never go in your mouth. Do not stab an entire steak with your fork and gnaw off it like a wolf; cut only one small piece of food at a time, and take small bites. This is useful for several reasons: it keeps you from doing horrific things with your mouth if the food turns out to be volcanically hot, and it allows you to chew and swallow gracefully before answering a question from another diner.
10. CHEW WITH YOUR MOUTH CLOSED. It's one of several things that separate us from the animals. Mastication, or for that matter anything that rhymes with it, should not be on public display. And if food is in your mouth, no noise should be coming out of it. Likewise, no bodily percussion. You may not be able to help it if your stomach rumbles, but you don't have to burp or fart at the table.
11. Table talk is not meant to be a political debate or a religious polemic, nor is it meant to be All About You. The best table conversation is good-natured, varied, friendly and not too serious, and it gives everyone a chance to contribute. Listen; don't just wait to talk. And since not everyone at the table has your cast-iron tum, don't give a blow-by-blow account of your last surgery, talk about the gory accident you passed on the way in, or discuss that program about cockroaches you saw on the Science Channel.
12. Even if you're Anthony Bourdain -- scratch that, especially if you're Anthony Bourdain -- don't criticize the food. If you don't care for something, stop after trying one bite. Should your host ask if you dislike a dish, "I'm sorry, but it's not to my taste" is a far more thoughtful response than "Hard-boiled eggs make me vomit." On the other end of the spectrum, even if you really enjoy a particular dish, you shouldn't vacuum the rest of it into your gaping maw or try to take home the leftovers. Ask your host if you can get the recipe. And if you drink, don't get blitzed.
13. Again, if this isn't a super-formal dinner, offer to help with cleanup. Do not use this as a chance to scarf down the remains of your favorite dish in the kitchen.
14. Even if you're having a fantastic time, do not be the last person to leave. Thank your host again for the invitation and the meal before you depart. You don't want to overstay your welcome; it's best to leave everyone wanting more.
15. Send your host a thank-you note. Yes, an old-fashioned snailmail thank-you note. Just use a plain notecard and envelope, and your most presentable writing.

Some of the items on this list may not come to you naturally. Few manners do. You may need to practice at home or in a restaurant for a while before these behaviors become second nature to you. But it's worth the effort. If you do these things, most hosts will LOVE you and would be more than happy to have you over again. That's a great feeling.