Good manners are very important for every human being, but there are 75 major good manners that the Quran teaches us and it is an eye-opener.

Quranic Guidelines for Ethical Behavior
Here is the list of 75 major Good Manners taught by Allah through the Holy Quran;

Never lie – (Quran 22.30)
Never spy on anyone – (Quran 49.12)
Do not show or feel triumphant elation – (Quran 28.76)
Do not insult anyone – (Quran 49.11)
Do not waste anything – (Quran 17.26)
Feed the needy – (Quran 22.36)
Do not backbite – (Quran 49.12)
Always Keep your oaths – (Quran 5.89)
Never take bribes – (Quran 27.36)
Honor your treaties – (Quran 9.4)
Control your anger – (Quran 3.134)
Do not spread gossip – (Quran 24.15)
Think good of other people – (Quran 24.12)
Be kind to guests – (Quran 51.24-27)
Do not hurt believers – (Quran 33.58)
Never be rude to parents – (Quran 17.23)
Turn away from hate or ill speech – (Quran 23.3)
Do not make fun of people – (Quran 49.11)
Walk in a humble manner – (Quran 25.63)
Respond to evil with good – (Quran 41.34)
Do not say what you Do not or can not do – (Quran 61.2)
Keep your promise and trust – (Quran 23.
Do not insult others’ false gods – (Quran 6.108)
Do not fraud people in trade – (Quran 6.152)
Do not take items without right – (Quran 3.162)
Do not ask unnecessary questions – (Quran 5.101)
Do not be miserly nor extravagant – (Quran 25.67)
Do not call others with bad or nicknames – (Quran 49.11)
Do not claim yourselves to be pure – (Quran 53.32)
Speak nicely, even to the ignorant – (Quran 25.63)
Do not ask for repayment (Monetary or anything) for favors – (Quran 76.9)
Make space for others at gatherings – (Quran 58.11)
If enemy wants peace, accept it – (Quran 8.61)
Return a greeting in a good manner – (Quran 4.86)
Do not remind people of your favors – (Quran 2.264)
Make peace between fighting groups – (Quran 49.9)
Talk moderately and lower your voice – (Quran 31.19)
Do not let hatred cause you to be unjust – (Quran 6.108)
Do not ask too many favors from others – (Quran 2.273)
Greet people when entering their home – (Quran 24.27)
Be honest, even against relatives or your ownself – (Quran 4.135)
Speak gently, even to the leaders of disbelievers – (Quran 20.44)
Do not criticise small contributions of others – (Quran 9.79)
Do not call the Prophet the way you call others’ – (Quran 24.63)
Try to make peace between husband and wife – (Quran 4.128)
Never call the Prophet from outside his rooms – (Quran 49.4)
Corruption and Oppression is worse SIN than killing – (Quran 2.217)
Teach others in a wise and good manner – (Quran 16.125)
Do not accuse others of immorality without proof – (Quran 24.4)
Consider wives of the Prophet like your mothers – (Quran 33.6)
Do not raise your voice above that of Prophet’s voice – (Quran 49.2)
Do not call someone a disbeliever (Kaafir) without knowing – (Quran 4.94)
Seek permission before entering anyone’s room – (Quran 24.59)
Knowing your enemies can possibly become your dear friends – (Quran 41.34)
Do not wrongly eat up the wealth of the vulnerable – (Quran 4.29)
Do not turn your cheek away from arrogant people – (Quran 31.18)
Forgive others, as you like Allah to forgive you – (Quran 24.22)
Seek Prophet’s permission when leaving his gathering – (Quran 24.62)
Do not hold secret meetings for sin, rather do so for devotion – (Quran 58.9)
Do not order others to do good while forgetting it yourself – (Quran 2.44)
Be patient with your teacher and follow his/her instructions – (Quran 18.67-69)
Do not frown, turn away or neglect those who come towards you – (Quran 80. 10)
If not able to help a poor person, at least speak nice words – (Quran 17.28)
Be lenient to those under you, and consult them in issues – (Quran 3.159)
Verify information from an authentic source before acting upon it – (Quran 49.6)
Do not remain in the Prophet’s home unnecessarily after a meal – (Quran 33.53)
Those who can should continue to spend on those less fortunate – (Quran 24.22)
Do not enter homes without permission and return if refused entry – (Quran 24.27-28)
Do not sit with those who mock religion until they change the subject – (Quran 4.140)
Say it’s not appropriate to talk of slander when it’s mentioned to you – (Quran 24.16)
If in need, ask the Prophet’s wives – (Quran 33.53)
Divorce in a humble manner instead of keeping and hurting your wife – (Quran 2.231)
Punish in a balanced manner to how you were hurt or be patient – (Quran 16.126)
The difference in language and color are signs of Allah, It does not mean any kind of superiority – (Quran 49.13)
Do not take any lady by power or force, do not take back marriage gift without an authentic reason and live with them in kindness – (Quran 4.19)

Add this too
Do not marry under age 🔞