There is no God except Allaah, Allaah is the only God, Allaah has no partner and none is like Allaah. Muhammad (sawaws) is the last Prophet of Allaah and there is no Prophet after Muhammad (s), Muhammad (s) is the Last Messenger of Allaah and he is the seal of Prophethood on whom the Holy Qur'aan was revealed. Ali (as) is his only successor (khalifa and janasheen) from whom the Imamat begins. Ali being the first Imam and the Twelfth Imam is Imam Muhammad Mehdi (as) (May Allaahh hasten his reappearance).
The word Etiquette means a code of behaviour. Islaam has taught us many good manners and good etiquettes. Infact Islaam is the only solution for a good universal society. Almighty Allaah who is the creator of the whole universe has guided us through many Prophets the code and conduct of life through the Holy Qur'aan, through Muhammad (s) and his Ahlul Bayt (as). Muhammad (s) and his Progeny are the perfect examples for us to follow.
Allaah has ordered us 'what to do' and 'what not to do', what is 'Halaal' (accepted in Islaam) and what is 'Haraam' (prohibited/forbidden in Islam), what is Makroo, what is Mustahab, Wajib, Sunnat, Ehtiyat e Waajib, etc. There are so many Islaamic Etiquettes out of which we would like to describe few viz.
Eating
Sleeping
Greeting
Dressing
Restroom
These can be discussed in detail as follows.
Eating:
Saying Bismillaah before eating or drinking. Prophet Muhammad (s) has said “Whenever one eats then he should say Bismillaah, and if forgets to say Bismillaah in the beginning then he should say Bismillaahi Awwalu wa Aakhiru”. Eating and Drinking with right hand. Sit and eat. During day time one should drink water while standing and during night time one should drink water while sitting. One should drink water in three sips. After drinking water one should send salawaat (blessings) on Imam Hussain (as) and Laanat on Yazid (la). Eat what is near, i.e eating from the part which is closer to you. Chew nicely which is good for digestion. One should not talk or speak while eating and drinking. Wash hands before and after eating. Allaah will reward those who eat together. Prophet Muhammad (s) has said “Eat together and read Bismillaah, in this, there is blessing for you”. Eat Halaal food. Do not waste or disrespect food and water. One should say Shukranlillaah (Thanks be to Allaah) after drinking or eating.
Sleeping:
Performing Wazu (oblution) before going to bed is spending whole night in Ibaadat (reward). Remember Allaah before going to bed. Our Imam Ali (A.S) said “He who sleeps too much at night, will lose something of his deeds (i.e., night prayers) which he cannot gain during the day-time”. Sleeping on one's right side facing the Qiblah (in Mecca) and not sleeping lying on one's stomach or naked. One should Knock the door and only after the permission get inside the room or house. Before going to bed recitation of Kalma, Surah's or/and Duas are good habits. One should make a habit of sleeping early and getting up early. Make sure that the feet is not facing towards Qibla. Before going to sleep one should think of all the things that have happened in the dayn and ask forgiveness (Tauba) to Allaah before going to bed.
Greeting:
Salaam is derived from the tri literal Arabic root word 'Sa La Ma' means Peace. From this verb Sa La Ma comes Islaam (Peaceful Religion) and from this word Sa La Ma come Muslim (Peaceful Person). When you see a Muslim greet him/her saying “As Salaamu Alaikum” which means 'Peace be upon you'. Our Prophet Muhammad (s) has said “Assalaamo Qablal Kalaam” (Say Salaam before talking). Imam Ja'far e Saadiq (as) has said "He who initiates a greeting (Salaam) is more beloved with Allah (swt) and His Messenger (s)". Imam Hussain ibn Ali (as) has said "Seventy rewards is the share of the one who initiates a 'greeting (Salaam)' and only one reward belongs to the one who returns the 'greeting (Salaam)”. Our Holy Prophet Muhammad (s) has said “O Muslims! You will not enter Paradise unless you are kind to each other, unless you warmly say Salaam (Peace be on you) to each other whenever you meet”. Apart from Salaam other greetings does not match the time, ocassion, etc, For example Good Morning in India is Good Night in US. Therefore timing differs the greeting. For example there is a death in a house and if one would wish him Good ******, here greeting as such does not suits the occasion. Whereas when a person greets As Salaamu Alaikum, it suits all time and all occasions. So spread Salaam, spread Peace.
Dressing:
The Islaamic etiquettes of dressing emphasise Modesty, humility and decency for both men and women. Islaam instructs both Muslim men and women to dress in a modest way. The dress should not be tight and it should not reveal your body or body shape. Muslim men are forbidden to wear silk and gold. Allaah has ordered Hijab for both men and women.
"Say to the believing men that they cast dawn their looks and guard their private parts; that is purer for them; surely Allah is Aware of what they do. And say to the believing women that they cast down their looks and guard their private parts and not display their ornaments except what appears there of, and let them wear their head-coverings over their bosoms, and not display their or name except to their husbands..." Holy Qur'aan (24:30-31).
A woman must cover her body and hair from the sight of non-mahramman. Beauty tempts man more than gold so It is unlawful for a man to look at the body and hair of a non-mahramwoman. Men's Hijaab is putting down his sight away from any non mahram women.
Restroom:
"Tahaarat" means cleanliness and purity. A person who is clean is called “Taahir”. Islaam has particular rules regarding personal hygiene when going to the Restroom. Step in the left leg while entering the Restroom and step out the right leg while coming out. Cleaning of private parts is obligatory in Islaam. It is Mustahab for men to do Istebra after urination. One should remain silent whilst on the toilet. Talking, answering greetings or greeting others is heavily disliked. One should not face nor turn one's back on Qiblawhilst relieving yourself. One should not urinate into stagnant water, as it makes the water impure and harms the people who may use it. Keep Restrooms clean. A person should avoid offering salaam (greetings) to a person who is relieving him/herself.
There are many such etiquette's but we have mentioned only few