A hostess gift is a gift which is given to the host or hostess of an event by guests. A small gift is generally considered appropriate for dinners and parties, while guests who are staying for several days may get something larger. The ideal gift is tasteful and elegant, reflecting the presumed good taste of the host or hostess, and it is also something which the recipient would not personally buy for him or herself. While the gift might seem like a quaint tradition to some people, it is still alive and well, and bringing a hostess gift to an event will indicate that you are well mannered and that you have been raised in polite society.
All sorts of things are suitable for hostess gifts. As a general rule, if you don't know the host of an event very well, you may want to stick with something fairly neutral, such as flowers, as flowers are generally appreciated. Another common choice of gift is wine, although you should be very careful about bringing wines, as some hosts do not drink, and others have very specific tastes in wine. Chocolates and fruit baskets are also not uncommon, along with gifts of fine soaps or lotions.
You should not necessarily expect to see your hostess gift displayed or used while you are present, especially if it is food or wine. Many hosts have planned very specific meals and wine pairings, and while your gift may be delightful and gratefully received, it may not be appropriate for the event in question. As a general rule, you will be kindly thanked and the gift will be put away; it is, after all, a gift, not a potluck item.
A well-mannered host will send you a thank you note within a few days, thanking you both for the gift and your presence at the event. It is also appropriate for you to send a thank you note, indicating your enjoyment of the party and your appreciation for the host's excellent hospitality. The exchange of small gifts and notes between hosts and guests keeps feelings of good will toward each other uppermost, and tends to result in more invitations to events.
You should never pick a hostess gift which is ostentatious or gaudy. The goal is not to impress the host, but rather to please him or her with a small, thoughtful item which reflects your appreciation for the invitation. Therefore, things like jewelry are generally frowned upon as gifts, and you may want to refrain from giving gift certificates as well.
One subset of the hostess gift, the housewarming present, allows for much more leeway. Housewarming presents can include various useful household items, from pot holders to tasteful lamps, and they are often greatly appreciated, especially by people who are moving into their first homes. If you know that your host needs a great deal of equipment, you may want to band together with a group of friends to ensure that the host does not receive eight eggbeaters or a similar excess of a particular item.