Angels were created out of light.
[Bahar-e-Shariat: Sadrush Sharia Allama Amjad Ali, Vol:1, Page: 23]

They were given the power to adopt any living-form they wish. Such as, Angel Jibrael (Peace be upon him) came to the Prophet Muhammad (Peace be upon him) taking up the face of a man; as narrated by Shaikh Umar (May Allah be pleased with him) that we were sitting around the Prophet (Peace be upon him) while a person having dark black hair and wearing a shiny white dress, came to him. His out look did not indicate that he was coming from any journey and none of us did recognize him either…
[See, Muslim: Imam Muslim, Vol: 1, Page: 272]

After he left, Prophet Muhammad (Peace be upon him) asked, “O Umar did you know who was he? He replied, “Allah and His Prophet know.” Prophet Muhammad (Peace be upon him) said, “He was Jibrael, and he came to teach you your religion”.
[Muslim: Imam Muslim, Vol: 1, Page: 273]

Some angels have wings as Allah, the Exalted, says in his book: ( All praise be to Allah, Creator of the heavens and earth, Appointer of the angels as Messengers who have two, three, and four wings. He adds to creation as He pleases)
[Holy Quran, Chapter: 35, Verse: 1 ]

Sometimes they have been granted more than four wings. Shaikh Abdullah Ibn-e-Masood (May Allah be pleased with him) narrated that the Prophet Muhammad (Peace be upon him) saw angel Jibrael (Peace be upon him) while he had six hundred wings.
[See, Bukhari: Imam Muhammad Bn Ismael Bukhari, Vol: 2, Page: 925]

Sometimes they embrace a way of appearance that nobody except the Prophet (Peace be upon him) can see them. As narrated by Syeda Aisha (May Allah be pleased with her) that once the Prophet (Peace be upon him) said to her, “O, Aisha! It is Jibrael who is greeting you.” She replied, “Peace be upon him and the mercy and blessings of Allah.” Then addressing the Prophet she said, “You see what I don’t.”
[Bukhari: Imam Muhammad Bin Ismael Bukhari, Vol: 2, Page: 219]

In addition, they do get down on earth looking like a cloudy thing. Shaikh Osaid Bin Huzair (May Allah be pleased with him) was reciting the Holy Quran at night. During this he saw something like a cloud containing lamps upon his head. Then he stopped his recitation fearing it might trample on him. On meeting with the Prophet (Peace be upon him), he told him what he saw. Prophet (Peace be upon him) explaining it said, “Those were angels who came to listen to you…”
[See, Muslim: Imam Muslim, Vol: 2, Page: 577]

The angels are not limited in their appearances to the forms that we have discussed. With the given ability by Allah, the Exalted, they can change their outlook easily. However, as some Hadiths signal out that they basically have a specific form in which they were created. Narrated by Syyeda Aisha (May Allah be pleased with her) that the Prophet Muhammad (Peace beupon him) has seen angel Jibrael (Peace be upon him) only twice in the form he was created.
[See, Muslim: Imam Muslim, Vol: 1, Page: 773 ]

Angels are neither male nor female.
[Bahar-e-Shariat: Sadrush Sharia Allama Amjad Ali Vol:1, Page: 24]

Thinking of them female and daughters of Allah, the Exalted, is wrong and baseless. Denying this type of thinking, Holy Quran says;
(Undoubtedly, those who do not believe in the Hereafter, name the angels with female names, and they have no knowledge thereof. They follow mere conjecture and verily the conjecture avails nothing against the conviction. )
[Holy Quran, Chapter: 53, Verses: 27, 28]

As Muslims, we have to believe in them all, regardless of their numbers and forms of appearances.
Allah, the Exalted, says;(O believers! Keep faith in Allah, and his Messenger and Book which He has sent
down upon His Messenger and the Book which has been sent down before. And who denies Allah, His Angels, His Books, His Messengers, and the Day of Judgment, has gone far , far , astry.)
[Holy Quran, Chapter: 4, Verse: 136]

Therefore, we have to respect them and must avoid making such a comment that leads to making fun of them or denigrating their status. As well as criticising their works is strictly not tolerable in any way. One who acts like an enemy of them, would be regarded as an enemy of Allah, the Exalted, as He said;
( Whoever is an enemy to Allah, His Angels, His Messengers, Jibrael, Mikael then certainly Allah is an enemy of infidels. )
[Holy Quran, Chapter: 2, Verse: 98]

All angels are sinless. We are not supposed to expect from them committing any sin intentionally or unintentionally, big or small. Allah, the Exalted, says member from the Fire whose fuel are ( O believers! Save yourselves and your family people and stones, over which are appointed stern and severe angels, who do not disobey the commands of Allah and do what they are commanded. )
[Holy Quran, Chapter: 66, Verse: 6 ]

In addition, as the total submission, to the will of Allah, the Exalted, angels do remember and extol Him.
( And to Allah Prostrate all that is in the heavens and all that are crawling on the earth and angels too, and they do not show arrogance. )
[Holy Quran, Chapter: 16, Verse: 49]

Angels have been made responsible for numerous duties by Allah, the Exalted, which they do perfectly.
Some angels are given the task of delivering the messages of Allah, the Exalted to His Prophets (Peace be upon them). Holy Quran indicates to this type of noble work in a beautiful way of expression saying:
(Say, whoever is an enemy to Jibrael, he has brought down the Quran to your heart by the command of Allah, confirming the former Books, and a guidance and Glad Tiding for Muslims. )
[Holy Quran, Chapter: 2, Verse: 97 ]

Some angels are directed to record the deeds of people. One of them sitting on the right shoulder writes down the good deeds and another one on the left shoulder records the bad deeds.
(When the two recording angels record the deeds; one sits on the right and the other on the left. Not he (person) utters a word but there is a guardian angel ready to record it.)
[Holy Quran, Chapter: 50, Verses: 17, 18]

Some angels are being ordered to breathe life into the fetus. Details of this duty was brought forward by the Prophet Muhammad (Peace be upon him) as he said, “An angel would be appointed by Allah, the Exalted, who asked, O Lord! A drop turned into a clot. O Lord! It turned into a piece of flesh. And then if Allah wants to complete its formation, the angels would say, O Lord! Male or female? O Lord! Prosperous or not-prosperous? What will his provision be? What will his age be? The angel writes all this……..”
[Bukhari: Imam Muhammad bin Ismael Bukhari, Vol: 2, Page:252]

An angel is made responsible for taking the souls at the time of death.
(Say, the angel of death who has been appointed over you causes you to die, and then you shall be returned to your Lord.)
[Holy Quran, Chapter: 32, Verse: 11]

On Friday, some angels are being appointed at the doors of the Mosques to register the names of the Prayers.
According to the Prophet (Peace be upon him) angels come to the Mosques on Friday and standing at the doors to register the names of the prayers chronologically. When the Imam sits on the pulpit to deliver the speech they fold up their registers and get ready to listen.
[See, Bukhari: Imam Muhammad bin, Vol: 2, Page: 217]

Angels make Durood on our beloved Prophet Muhammad (Peace be upon him) as Holy Quran indicating to this topic announces (Undoubtedly, Allah and His angels send blessings on the Prophet, the communicator of unseen. )
[Holy Quran, Chapter: 33, Verse: 56]

And when a follower of the Prophet (Peace be upon him) makes Durood on him it would be presented to him by an angel, appointed by Almighty Allah for this purpose. Disclosing this secret, our Prophet (Peace be upon him) said, “There is an angel of Allah, the Exalted, who was provided with the power of hearing to the whole creation, will stand near my grave till the Last Day after my death. He will convey me the Durood, made by any of my followers on me with his name including his father, saying O Muhammad (Peace be upon him) such person made Durood on you then Allah, the Exalted, will give him the reward ten times for each Durood.”
[Anwar-e-Ahmadi: Allam Shaikh Muhammad Anwarullah, Page; 71]

Along with this mean of carriers, our Prophet (Peace be upon him) listens to our Durood and Greetings directly too. Clarifying this unique ability he said, “Not a person makes Durood on me but his voice reaches to me…”
[Anwar-e-Ahmadi: Allam Shaikh Muhammad Anwarullah, Page: 71]

Some angels are appointed by Allah, the Exalted, to move around the world in search of the programmers of the remembrance of Allah, the Exalted.
[See, Muslim: Imam Muslim, Vol: 7, Page: 464]

Some angels are being directed to ask forgiveness for Muslims and say “Aameen” after the supplications.
[See, Bukhari: Imam Muhammad Bin Ismael, Vol: 2, Page: 220, 222]

Along with those above duties of angels, they do have various responsibilities related to the world and its movements causing rain, blowing trumpet on the Last Day, directing clouds, and etc.
[See, Bahar-e-Shariat: Sadrush Sharia, Vol: 1, Page;23 ]