The wedding feast of his daughters was very simple:

Buraydah (a Companion) narrated that when ‘Ali proposed to Faatimah, the Prophet of Allah, sallallaahu ‘alayhi wa sallam, said: “A wedding must have a wedding feast.” So Sa’d (a Companion) said that he would bring a sheep, and another person said he would bring such and such amount of wheat.

It is better to hold the wedding feast after the consummation of the marriage because this is the practice of the Prophet of Allah, sallallaahu alayhi wa sallam. However, if this is not possible then one can make it before the consummation, during the marriage contract, or even after it.