When you hear Westerners(西方人) say "Drop in anytime"(随时来玩) or "Come and see me soon", you should realize that it doesn't mean you are welcome to come over to their house anytime. It's wise to telephone before visiting someone.
Never accept an invitation unless you really plan to go. You may refuse by saying, "Thank you for inviting me, but I may not be able to come. " If you are unable to come after accepting the invitation, be sure to tell those who invite you in advance(提前) that you will not be there.
When you have accepted the invitation to a party or a dinner, it is polite to bring small gifts with you, such as bottles of drink, flowers, and some others. Sometimes Westerners may take you out to dinner in a restaurant and it does not necessarily mean that he is going to pay the bill at the end of the meal. He might want you to "go Dutch", which means each person pays his own bill.