Sometimes, the most subtle movements, facial expression, body language, terminology etc. can be the difference between making someone feel good or the opposite. Examples are INFINITE.
Just one [it's almost 2am:)]: People are often in a rush. Therefore, when someone wants to talk, the hurried people will make the person feel very unwanted. "I can't talk. I gotta run". What a WONDERFUL feeling:):).
I have been privigeled to know two of the most sought after and busy people on G-d's green earth. The Tolna Rebbe Shlita and Rav Yaakov Katz Shlita. I have NEVER met two people who were so adept at giving me the feeling that they have ALL the time in the world and that ALL they want to do is talk to me. Complete attention with a calming and peaceful demeanor. A mechaye. I have heard that other tzadikim [such as the Lubavitcher Rebbe] had/ have this quality as well.
Or take Rav Genechovski as a f'rinstence. Someone once wanted to speak with him and he agreed but added "Daven for me that I get back to Bnei Brak in time for hadlakos neiros chanukah." The person understood that the Rav has to go. He was just TOO SENSITIVE to say "I can't talk now. I am in a huge rush" so he hinted instead.
Please sweet friends, pay careful attention how you relate to others. And the rule of rules: Try to make sure that every interaction you have leaves the other person feeling just a little bit happier. It could be with a smile or a compliment or just listening to him or her speak. When you talk to a yeshiva bochur, ask him to share something he learned. When you meet a six year old, ask him the name of his friends or teachers and what he wants to be when he grows up. If he says "Policeman" don't try to dissuade him....:). If you are talking to an old [or young] Bubbe, ask her about her grandchildren. It is EASY to make someone feel good. It is also easy to make someone feel badly. The difference is a hairsbreadth כחוט השערה.
If I don't end this post soon, I am not going to get ANY sleep:):).