Ways of offering witr prayer:
1 – To pray them one after another, with one tashahhud, because of the hadeeth of ‘Aa’ishah (may Allaah be pleased with her) who said: The Prophet (peace and blessings of Allaah be upon him) used not to say the tasleem in the (first) two rakahs of Witr. According to another version: “He used to pray Witr with three rak’ahs and he did not sit except in the last of them.” Narrated by al-Nasaa’i, 3/234; al-Bayhaqi, 3/31. al-Nawawi said in al-Majmoo’ (4/7): it was narrated by al-Nasaa’i with a hasan isnaad, and by al-Bayhaqi with a saheeh isnaad.
2 – Saying the tasleem after two rak’ahs, then praying one rak’ah on its own, because of the report narrated from Ibn ‘Umar (may Allaah be pleased with him), that he used to separate the two rak’ahs from the single rak’ah with a tasleem, and he said that the Prophet (peace and blessings of Allaah be upon him) used to do that. Narrated by Ibn Hibbaan (2435); Ibn Hajar said in al-Fath (2/482): its isnaad is qawiy (strong).
But if he prays Witr with five or seven rak’ahs, then they should be continuous, and he should only recite one tashahhud in the last of them and say the tasleem, because of the report narrated by ‘Aa’ishah (may Allaah be pleased with her) who said: The Messenger of Allaah (peace and blessings of Allaah be upon him) used to pray thirteen rak’ahs at night, praying five rak’ahs of Witr, in which he would not sit except in the last rak’ah. Narrated by Muslim, 737.
And it was narrated that Umm Salamah (may Allaah be pleased with her) said: The Prophet (peace and blessings of Allaah be upon him) used to pray Witr with five or seven (rak’ahs) and he did not separate between them with any salaam or words. Narrated by Ahmad, 6/290; al-Nasaa’i, 1714. al-Nawawi said: Its isnaad is jayyid. Al-Fath al-Rabbaani, 2/297. and it was classed as saheeh by al-Albaani in Saheeh al-Nasaa’i.
If he prays Witr with nine rak’ahs, then they should be continuous and he should sit to recite the tashahhud in the eighth rak’ah, then stand up and not say the tasleem, then he should recite the tashahhud in the ninth rak’ah and then say the tasleem. It was narrated in Muslim (746) from ‘Aa’ishah (may Allaah be pleased with her) that the Prophet (peace and blessings of Allaah be upon him) used to pray nine rak’ahs in which he did not sit except in the eighth, when he would remember Allaah, praise Him and call upon Him, then he would get up and not say the tasleem, and he would stand up and pray the ninth (rak’ah), then he would sit and remember Allaah and praise Him and call upon Him, then he would say a tasleem that we could hear.
If he prayed Witr with eleven rak’ahs, he would say the tasleem after each two rak’ahs, then pray one rak’ah at the end.
The less perfect way of praying Witr and what is to be recited therein:
The less perfect way in Witr is to pray two rak’ahs and say the tasleem, then to pray one rak’ah and say the tasleem. It is permissible to say one tasleem, but one should say one tashahhud not two, as stated above.
In the first rak’ah one should recite Sabbih isma rabbika al-‘a’la (“Glorify the name of your Lord, the Most High” – Soorat al-A’la 87). In the second one should recite Soorat al-Kaafiroon (109), and in the third Soorat al-Ikhlaas (112).
Al-Nasaa’i (1729) narrated that Ubayy ibn Ka’b said: The Messenger of Allaah (peace and blessings of Allaah be upon him) used to recite in Witr Sabbih isma rabbika al-‘a’la (“Glorify the name of your Lord, the Most High” – Soorat al-A’la 87), Qul yaa ayyuha’l-kaafiroon (“Say: O disbeliever…” – Soorat al-Kaafiroon 109) and Qul Huwa Allaahu ahad (“Say: He is Allaah, the One” – Soorat al-Ikhlaas 112). Classed as saheeh by al-Albaani in Saheeh al-Nasaa’i.
All these ways of offering Witr prayer have been mentioned in the Sunnah, but the best way is not to stick to one particular way; rather one should do it one way one time and another way another time, so that one will have done all the Sunnahs.
And Allaah knows best.