Firstly: Sunan and Etiquettes of Ablution
1. Tasmiyah  Tasmiyah is the act of saying the basmalah, which is the statement recited at the beginning of all but one Qur’anic chapters.
The majority of jurists have deemed it mustahabb to begin the ablution with tasmiyah. This is the position of the Hanafis, Malikis, Shafi`is, and a narration among the Hanbalis.
It is a sunnah to perform siwak when about to perform ablution.  This has been discussed in the sunan of the fitrah.
3. Washing the palms thrice
It is a sunnah to wash the hands until the wrists  Rusghayn is the dual form of rusgh, which is the joint between the palm and the forearm. at the beginning of ablution for other than the one who has just woken up from sleep. Consensus on the matter has been quoted by Ibn al-Mundhir and al-Nawawi.
4. Exaggerating gurgling and sniffing up water
It is a sunnah to exaggerate gurgling and sniffing up water,  Exaggeration in gurgling is spreading the water vigorously around one’s mouth, and exaggeration in sniffing up water is through allowing it to reach the nasal passage (khayshum). and this is by agreement of the four schools of jurisprudence.
5. Blowing the nose
- The ruling of blowing the nose
Blowing the nose is one of the sunan of ablution, and this is by agreement of the four schools of jurisprudence.
- How to blow the nose
After sniffing up water as part of ablution, one would let out air, water, and any discharge from the nose using the left hand on the nostrils. This is by agreement of the four schools of jurisprudence.
6. Allowing water to reach within the beard
The majority of jurists have deemed it mustahabb to allow water to reach within the thick beard.  Doing takhlil of water throughout a thick beard is to allow water to enter it and making it reach the skin with the fingers. This is the correct position among the Hanafis, the position of the Shafi`is, Hanbalis, an opinion among the Malikis, and the view of the majority of scholars.
7. Allowing water to reach between the fingers and toes
If water reaching between the fingers and toes is only possible through consciously allowing it to do so, then it is wajib. If it naturally does so, then it is mustahabb. This is the position of the majority: Hanafis, Shafi`is, Hanbalis, and an opinion among the Malikis.
- The description of how to allow water to reach between the fingers
To allow the water to reach between the fingers one would intertwine the fingers of the two hands. This is the position of the majority: Hanafis, Shafi`is, and Hanbalis.
- The description of how to allow water to reach between the toes
To allow the water to reach between the toes one would use their pinkie finger.  Ibn `Uthaymin said: “Saying that this act is sunnah when it is not confirmed as an act performed by the Prophet ﷺ is worthy of analysis. It should be said that this is simply seeking of betterment (istihsan) from some scholars, but it should not be adhered to as an act of sunnah.” Al-Sharh al-Mumti` (175/1). This is by agreement of the four schools of jurisprudence.
8. Moving a ring and its like
It is mustahabb to move a ring or anything similar to it if one is certain water has reached underneath it, otherwise it is wajib to remove it or slide it out of position temporarily. This is the position of the majority: Hanafis, Shafi`is, and Hanbalis.
9. Washing each part three times
It is a sunnah to wash each body part in ablution thrice, and this is the general position. Consensus has been quoted on the matter by: al-Tahawi, Ibn `Abd al-Barr, Ibn Rushd, al-Nawawi, and al-`Ayni.
-The ruling of exceeding three times in ablution
Exceeding washing three times  Al-Nawawi said: “What is meant by three: is that which holistically covers the body part.” Sharh al-Nawawi `ala Sahih Muslim (109/3). The one performing ablution should keep in mind the amount of water being used. Al-Nawawi has quoted a consensus over the prohibition of wasting water. in ablution is makruh, and this is by agreement of the four schools of jurisprudence.  In Hashiyat Ibn `Abidin (133/1) it is stated: “Whoever considers it a sunnah has transgressed, due to him considering what isn’t an act of closeness to Allah as an act of seeking closeness to Him.”
10. Starting with the right
It is mustahabb to start with the right first then the left when washing the symmetrical body parts in ablution.  Whoever leads with his left then his ablution is valid and he does not need to repeat by consensus. This is quoted by: Ibn al-Mundhir, Ibn `Abd al-Barr, and Ibn Taymiyyah. Consensus has been quoted on this matter by: Ibn `Abd al-Barr, Ab al-Walid al-Baji, Ibn al-`Arabi, Ibn Qudamah, al-Nawawi, and al-`Ayni.
11. Massaging  Dalk is moving the hand over the body part.
The majority of scholars have deemed it mustahabb to massage the body parts which are wajib to wash.  However, if water reaching the respective body parts will only take place adequately through dalk, then it is obligatory. This is the position of the Shafi`is, Hanbalis,  Hanbalis have specified it for body parts from which water easily slides off and trickles down. and an opinion among the Malikis.
12. Starting with the front of each body part
It is liked to start each body part from its front.  Starting with the fingers when he washes the hands, and where the hair normally grows when wiping over the head, and from the toes when washing the feet. This is the position of the majority: Hanafis, Malikis,  Among them are those who considered it a virtue, and others who considered it a sunnah. and Shafi`is.
13. Supplicating once ablution is concluded
It is a sunnah to say at the conclusion of ablution: “I bear witness there is no god but Allah, and that Muhammad is the slave of Allah and His Messenger.”
14. Praying two units of prayer
It is mustahabb for the one who has performed ablution to pray two units of prayer after ablution. The majority of scholars have explicitly mentioned this: Hanafis, Shafi`is, and Hanbalis.
Secondly: Permissible Acts in Ablution
1. Talking during ablution
It is not haram to talk when performing ablution, and this is by agreement of the four schools of jurisprudence.  Malikis considered excessive talk makruh in ablution. Al-Nawawi said: “al-Qadi `Iyad narrated in his explanation of Muslim that the scholars disliked talking during ablution and ritual washing. This dislike is borne of leaving off what is preferred, as there is no authentic prohibition regarding it, so it is not makruh unless with the meaning of leaving off what is better.” Al-Majmu` (466/1)
2. Seeking the aid of others in ablution
It is permissible to seek the aid of another in performing ablution. This is the position of the Hanbalis, an opinion among the Hanafis, and a position among the Shafi`is. It is also the choice of Ibn Baz and Ibn `Uthaymin.
It is permissible to dry off the washed body parts from the wetness of ablution. This is by agreement of the four schools of jurisprudence.
Thirdly: What is Not Legislated in Ablution
1. Supplicating when washing each body part
Supplicating when washing each body part during ablution is not legislated. This is the position of the Shafi`is and Hanbalis, an opinion among the Malikis, and the choice of Ibn al-Qayyim, al-San`ani, Ibn Baz, and Ibn `Uthaymin.
2. Wiping the neck
Wiping the neck is not legislated as part of ablution,  Some scholars have expressed it as makruh, and others as bid’ah (innovation). and this is the position of the majority: Malikis, Shafi`is, Hanbalis, and an opinion among the Hanafis.
3. Lengthening the ghurrah and the tahjil
- The meaning of the ghurrah and the tahjil
The origin of the ghurrah is a shining white colour that appears on the head of some horses. It was then used as a reference to beauty, prominence, and noble mention. What it refers to here is the light in the faces of the Ummah of Muhammad ﷺ.
Tahjil is whiteness that appears in the bases of three out of four legs of a horse, and it comes from hijl, which is the anklet. What it refers to here is the light that is in the feet of the Ummah of Muhammad ﷺ.
Lengthening the ghurrah and the tahjil refers to washing more than is necessary in the body parts of ablution.
- The ruling of lengthening the ghurrah and the tahjil
Lengthening the ghurrah and the tahjil is not legislated. This is the position of the Malikis, a narration from Ahmad, and the choice of Ibn Taymiyyah, Ibn al-Qayyim, Ibn Baz, and Ibn `Uthaymin.