The Ladies' Book of Etiquette, and Manual of Politeness

When your visit is over, give a present to each of the servants, varying its value, according to the length of your visit or the services you may have required. You will add to the pleasure by presenting such gifts yourself, with a few pleasant words. Never compare the house you may be visiting with your own, or any other you may visit. Avoid also speaking of any house where you may have been a guest in terms of overpraise, giving glowing pictures of its splendor. Your hostess may imagine you are drawing comparisons unfavorable to your present residence. Also avoid speaking unfavorably of any former visit, as your hostess will naturally conclude that her turn for censure will come as soon as your visit is over. If any family secret comes to your knowledge while you are on a visit in that family, remember the hospitality extended to you binds you to the most inviolable secrecy. It is mean, contemptible, rude, and ill-bred to make your entertainers regret their hospitality by betraying any such confidence; for it is as sacred a confidence as if you were bound over to silence in the most solemn manner. After paying a visit, you should write to your hostess as soon as you reach home again; thank her in this letter for her hospitality, speak warmly of the enjoyment you have had in your recent visit, and mention by name every member of the family, desiring to be remembered to all.