“Khushoo‟ in prayer happens when a person empties his heart for it (prayer), and focuses on it to the exclusion of all else, and prefers it to everything else. Only then does he find comfort and joy in it, as the Prophet (peace and blessings of Allah be upon him) said: „... and my joy has been made in salaah.‟” (Tafseer Ibn Katheer, 5/456. The hadith is in Musnad Ahmad, 3/128 and Saheeh al-Jaami‟, 3124).
Learn tafseer of words you recite: knowing the meaning of the words recited from the Quran in sallah makes us have something to think of other than dinner or what happened at work. It's very important to know the meaning of the words.
By repeating the words of the adhaan after the muezzin;
Moving at a measured pace during prayer: Prophet (peace and blessings of Allah be upon him) used to move at a measured pace during salaah, allowing every bone to return to its place. (Its isnaad is classed as saheeh in Sifat al-Salaat, p. 134, 11th edn. Ibn Khuzaymah also classed it as saheeh as mentioned by al-Haafiz in al-Fath, 2/308).
Remembering death whilst praying: Prophet (peace and blessings of Allah be upon him) said: “Remember death in your prayer, for the man who remembers death during his prayer is bound to pray properly, and pray the prayer of a man who does not think that he will pray any other prayer.” (al-Silsilat al-Sahihah by al-Albaani, 1421.
Pausing at the end of each ayah: this is more helpful in understanding and thinking about the meaning, and it is the Sunnah of the Prophet (peace and blessings of Allah be upon him), as Umm Salamah (may Allah be pleased with her) described how the Messenger of Allah (peace and blessings of Allah be upon him) would recite, “Bismillah il-Rahmaan il-Raheem”, and according to one report, he would pause, then say, “Al-hamdu Lillaahi Rabbi‟l- „Aalameen, al-Rahmaan, al-Raheem.” Then according to one report, he would pause, then say, “Maaliki yawm il-deen,” and he would break up his recitation ayah by ayah. (Reported by Abu Dawood, no. 4001; classed as Saheeh by al-Albaani in al-Irwaa‟, where its isnaads are described. 2/60).
Beautify your voice: Another way of helping oneself to have khushoo‟ is by making one‟s voice beautiful when reciting. This is something that was advised by the Prophet (peace and blessings of Allah be upon him), as when he said, “Beautify the Qur‟an with your voices, for a fine voice increases the Qur‟an in beauty.” (Reported by al-Haakim, 1/575; Saheeh al- Jaami‟, no. 3581).
Knowing that Allah responds to prayers : If everyone kept it in mind when he prays, he would attain immense khushoo‟ and al-Faatihah would have a great impact on him. How could it be otherwise, when he feels that his Lord is addressing him and giving him what he is asking for?
Praying with a barrier (sutrah) in front of one and praying close to it
Placing the right hand on the left hand on the chest:
Looking at the place of prostration: It was reported from „Aa‟ishah that “the Messenger of Allah (peace and blessings of Allah be upon him) used to pray with his head tilted forward and his gaze lowered, looking at the ground.” (Reported by al-Haakim, 1/479. He said it is saheeh according to the condition of the two Shaykhs [al-Bukhari and Muslim], and al-Albaani agreed with him in Sifat al-Salaah, p. 89).