Do you want to be more sophisticated? Here's how.

Be polite and charming. Being polite and charming is mostly about being aware of your companions and their feelings. Is your dinner companion an avid golfer? Then let him/her discuss golf. Express an interest in the subject. Respond intelligently with whatever knowledge you may have that relates. If you know nothing about golf, let them talk. Human beings like to talk; the best conversationalists let others talk and keep the conversation moving with leading questions and the occasional meaningful, insightful, or witty comment. A leading question is one that "leads" your conversation partner to speak at more length than a simple yes or no answer. Never interrupt and never forcefully assert your knowledge. Being selflessly aware of your companions' interests can give the impression of charm.

Understand etiquette. Etiquette is a system of manners and customs that each individual culture devises. The main purpose of etiquette in most modern cultures is to make those around you more comfortable or at ease. Be careful, however, because etiquette is different in each culture. It's important to study the rules of etiquette that your culture/society has adopted. There are plenty of online resources for that type of research. Use them. Study what is appropriate at various types of social functions, not just at the dinner table. And, when in doubt, ask yourself "What will make my companions more comfortable--behavior A or behavior B?"

Dress well. It's important to know what colors and what clothing styles suit you. By reading fashion magazines, you can get a better understanding of current trends but be wary of being too trendy--you can go broke keeping up with this season's latest. It's better to build your wardrobe on a solid foundation of classics that don't change much from season to season but that can easily be accessorized to keep them current. Do your research and find out what doesn't change much but also works for your personal style and body type. Get the advice of a professional if you don't know.

Know what you're talking about. It's important to be as knowledgeable about as broad a range of subjects as you can be. Read! Read everything, from newspapers to non-fiction books to magazines to scientific journals to literature. Being actually knowledgeable about a subject keeps you from appearing like that know-it-all buffoon who talks too much at parties and doesn't really know much about anything. You know who I mean. You've seen him/her before. Avoid that by actually being knowledgeable and by not speaking up when you don't know anything. Abraham Lincoln once said, "Better to remain silent and thought a fool than to speak out and remove all doubt." If you want more specific direction, read up on your friends' interests. At least you'll be able to listen intelligently.
Read.Do you feel overwhelmed by the amount of material that one can read? Start with newspapers. Find a good national or local paper ,preferably one that covers international events. Good magazines like TIME are easy to read and entertaining. If you can't subscribe to a newspaper www.nytimes.com is a good place to start. Here's a secret to coming across as well read - read abridged ( shortened) versions of classics or read book reviews. Book reviews give you enough information to carry on conversations about famous or award winning authors. Find a category of fiction you like and read up at the local library. If the size of books frighten you, you are not ready to become a sophisticated adult. Don't forget about poetry - start with a poet whose work you studied at school and go on from there. And one more final advice- if you are truly desperate and absolutely can't read the book- see a movie version of it!

Be respectful. First, it's important to respect yourself. Understand your strengths and weaknesses. Learn to appreciate your strengths and forgive your weaknesses while improving those that you can. From this base, you'll have the sensitivity and confidence to be respectful of others' feelings and needs.

Start small.
Put others' needs and interests before your own.
Educate yourself and the rest will follow.
Experience is a good teacher, but only if you think about your experiences afterwards.

There is such a thing as trying too hard. Be wary of it. Be your natural self, but be AWARE of both your own behavior and the feelings of your companions.