How can a Muslim pray with proper presence of mind and humble focus (Khushu`), without being distracted by things outside of the prayer?

He stood up to make up what he had missed of the prayer when the imam had not yet completed his salaam at the end of the prayer

Ruling on raising the hands between prostrations

Is it recommended to do the Sunnah prayers all the time, or is it better not to do them sometimes so that they do not become like the obligatory prayers?

He recited quietly at the beginning of his prayer, then someone else joined him; should he complete it reciting quietly or out loud?

Ruling on reciting al-Faatihah out loud then reciting the surah that comes after it quietly, in the same rak‘ah

It is mustahabb to continue pointing with the finger during the tashahhud until the second tasleem is complete

There is nothing wrong with breaking up a single verse over two rak‘ahs, but that is contrary to what is preferable

Should one who joins the prayer late recite the opening du‘aa’?

Keeping the arms away from the body when bowing and prostrating in a congregational prayer