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)

Another instruction from the Prophet on drinking
Allah’s Apostle said, “Whenever anyone of you drinks water, he should not breathe in the drinking utensil”
Sahih Al-Bukhari Hadith 1.155 Narrated byAbu Qatada (ra)

It is permissible to drink while standing, however it is better to drink while sitting.

Narrated Aboo Hurayrah (may Allaah be pleased with him): Allah’s Messenger (peace be upon him) said: “None of you should drink while standing; and if anyone forgets, he must vomit.” Sahih Muslim:5022

Ibn Abbas, may Allah be pleased with them, reported: I served (water of) Zamzam to Allah’s Messenger (may peace be upon him), and he drank it while standing.
Hadith Sahih Muslim : 3776

Narrated An-Nazzal (may Allaah be pleased with him): All came to the gate of the courtyard (of the Mosque) and drank (water) while he was standing and said, “Some people dislike to drink while standing, but I saw the Prophet (peace be upon him) doing (drinking water) as you have seen me doing now.” Sahih Al-Bukhari Hadith 7.519 Narrated by An-Nazzal

Imam Nawawee (may Allaah have mercy on him) said: “There is no contradiction in these ahaadeeth, praise be to Allah, and none of them are daeef (weak). Rather they are all saheeh. The correct view is that the forbidding mentioned in them is to be understood as meaning that it is disliked. The fact that the Prophet (peace and blessings of Allah be upon him) drank whilst standing indicates that it is permissible to do so. This is all that needs to be said on the matter.”

4. Sneezing
When someone sneezes, they should praise Allah by saying “Alhamdulillah’ “(Praise be to Allah.)

If you here someone sneezing and praising Allah, you should ask Allah to bestow His Mercy on them by saying “Yarhamukallaah” ( May Allah Azawajal Bless you).”

If someone says this to you, you should reply, “Yahdeekumullaahu wayuslihu baalakum”
(May Allah give you guidance and improve your condition).

5. Greeting
It is the duty of all Muslims to great each other by sayin “As-Salaamu alaykum”(peace be upon you)

Narrated Aboo Hurayrah (may Allaah be pleased with him): The Prophet (peace be upon him) said, “Allah created Adam, making him 60 cubits tall. When He created him, He said to him, Go and greet that group of angels, and listen to their reply, for it will be your greeting (salutation) and the greeting (salutations) of your offspring.’ So, Adam said (to the angels), “As-Salamu Alaikum” (i.e. Peace be upon you).

The angels said, “As-salamu Alaika wa Rahmatu-l-lahi” (i.e. Peace and Allah’s Mercy be upon you).

Thus the angels added to Adams salutation the expression, ‘Wa Rahmatu-l-lahi,

Any person who will enter Paradise will resemble Adam (in appearance and figure). People have been decreasing in stature since Adams creation.” Sahih Bukhari 4:55:543