When communicating with Americans, there are two occasions to naturally express congratulations and friendship through gifts, one is during Christmas every year, and the other is when you arrive and leave the United States. If you are working, you can send some office supplies or choose some exquisite handicrafts with ethnic characteristics. In the United States, inviting guests to dinner, drinking a glass of wine, or going to a villa for the weekend is regarded as a more common form of "gift". You just need to thank it, and you don't need to do any other rewards. Generally speaking, you don't need a big gift to visit an American home. Just bring some small gifts such as flowers, wine and handicrafts. If you go to dinner empty-handed, it means that you will invite you back.
American gift giving is characterized by simplicity, informality and practicality. The value and form of a gift are not important, just simple and practical, so a bunch of flowers, a new book, a box of chocolates or a bottle of wine, etc.