Answered by Shaykh Faraz Rabbani
What is the correct or preferred method to pray the voluntary prayers?
Answer:
Walaikum assalam wa rahmatullah,
Supererogatory prayers are of two types:
1) Those related to the obligatory prayers;
2) Those not related to the obligatory prayers.
Each has rulings related to it.
See:
The sunnas associated with the obligatory prayer
The Fiqh of Voluntary (Nafl) Prayers: An exposition of the prayers not directly related to the obligatory prayers
Wassalam,
Faraz Rabbani