1. Praying for someone who does good to you
Praying for the one who treats you kindly by saying “Jazak Allaahukhairan”
It was narrated that Usaamah ibn Zayd (may Allaah be pleased with him) said: The Messenger of Allah (peace be upon him) said: “Whoever has a favour done for him and says to the one who did it,JazakAllaahu khairan, has done enough to thank him.(May Allah reward you for the good)
2. Shaking hands with the opposite gender
It is NOT permissible for a man to shake the hands of a non –mahram[ woman]
Narrated Maqal ibn Yassaar (may Allaah be pleased with him) who said: The Messenger of Allah (peace be upon him) said: “If one of you were to be struck in the head with an iron needle, it would be better for him than if he were to touch a woman he is not allowed to.”
(al-Tabaraani; classed as saheeh by al-Albaani in Saheeh al-Jaami, 5045)
3. Drinking
The Prophet (peace be upon him) said: “Do not drink water in one gulp (or one breath) like a camel, but take it in two or three installments (with break for breaths);
take the name of Allah (i.e. recite Bismillah) when you start drinking and praise Him (say Alhamdulillah) when you finish.” Al-Tirmidhi Hadithh 758 Narrated byAbdullah ibn Abbas (ra)