Answered by Shaykh Faraz Rabbani
Can the sujud al-sahw be done in every prayer to ensure it is valid?
It would be prohibitively disliked, sinful, and a reprehensible innovation to perform the Sujud al-Sahw for every prayer without need. Forgetfulness prostrations are only required when one forgetfully leaves a necessary (wajib) action in prayer. It is not required nor permitted for any other action. [Shurunbulali, Nur al-Idah]
You should strive to learn the necessary (wajib) elements of prayer. Any reliable manual of Hanafi fiqh will list these for you.
Also another basic assumption is that actions are valid and sound until proven otherwise.
Note that there is a difference between leaving an obligatory (fard) action in prayer and leaving a necessary (wajib) action – the former invalidates prayer; the latter renders it deficient (though valid).
Past prayers in which wajib actions were omitted do not have to be repeated. It is obligatory to make up prayers in which obligatory (fard) actions–conditions or integrals–of the prayer were omitted. If this is the case, you should how many prayers you have to make up and set a consistent and sustainable schedule of making up the prayers.
And Allah alone gives success.
[Shaykh] Faraz Rabbani
Shaykh Faraz Rabbani spent ten years studying with some of the leading scholars of recent times, first in Damascus, and then in Amman, Jordan. His teachers include the foremost theologian of recent times in Damascus, the late Shaykh Adib al-Kallas (may Allah have mercy on him), as well as his student Shaykh Hassan al-Hindi, one of the leading Hanafi fuqaha of the present age. He returned to Canada in 2007, where he founded SeekersGuidance in order to meet the urgent need to spread Islamic knowledge–both online and on the ground–in a reliable, relevant, inspiring, and accessible manner. He is the author of: Absolute Essentials of Islam: Faith, Prayer, and the Path of Salvation According to the Hanafi School (White Thread Press, 2004.) Since 2011, Shaykh Faraz has been named one of the 500 most influential Muslims by the Royal Islamic Strategic Studies Center.