Another aspect of derech eretz (proper social conduct) is to not bother one’s fellow by looking at his personal affairs. If one’s fellow wishes to do something privately, such as a mitzvah or giving charity, then you, too, should be private about it. Do not upset him by looking at what he is doing. And whatever you did see, do not tell to others, and make it as though you know nothing about it.
Once a person purchased some item, do not express any negative opinion about it; praise it instead. This is all the more so if it is an item that someone else purchased on his behalf. For if you denigrate it to his face, it will upset him and the one who purchased it.
When asking a favor of another person, make sure that you are not overburdening him. Nor should you send many friends to influence him to do the favor. And if the one asking for the favor is a person of stature — the type of person that others are embarrassed to turn down — he must be extra to not ask any favors for himself, because aside from the fact the other person will resent him, it is also possibly a form of stealing.
One should always choose a seat that is appropriate for people of lesser stature and should not go up until he is entreated to do so.
Always give slightly more honor to people than they seem to deserve. How can it hurt to give a little extra honor? And if that person is pleased by that honor, it will be considered a mitzvah for you. Guests and Torah scholars especially should be given extra honor, for that is doing kindness with them. We have learned in the Mishnah: “Who is honorable? He who honors others.” It takes insight to know what pleases different people. For there might be one thing that you think will find favor in the eyes of people, but in fact people do not like it. So, one needs to explore, inquire, and ask others about best manners and behaviors. Pray to Hashem that He guide you that you do what is good and proper in the eyes of God and Man. Whatever you do, should be for the sake of Heaven. Hashem will not withhold good from those who walk uprightly. Hashem will give grace and honor.