Focusing our eyes on the place of prostration while standing; on the feet while bowing down; on the hands placed on knees while sitting upright; and on the shoulders while turning our face to the right and to the left at the end of the prayer.
Prostration of Forgetfulness (sajdatus sahw)
The prostration of forgetfulness is performed when some requirements are forgotten or done incorrectly in order to make up for the error by making two extra prostrations and then reciting “at-Tahiyyat” and as-Salah alan nabiyy (the blessing on the Prophet) before ending the prayer.
Such acts as forgetting to read the Qunut supplication in the Witr prayer; bowing down before reading passages from the Qur’an after al-Fatiha; forgetting to sit upright after the first two units; and not doing prostration if a verse of prostration is recited in the prayer, require the prostration of forgetfulness.
However, if one forgets to perform the prostration of forgetfulness and ends the prayer without performing it, it is not necessary to perform the prayer over again.
Source: Osman Nuri Topbaş, ISLAM SPIRIT AND FORM, Erkam Publications