Hadhrat Mawlana Mohammad Taqi Usmani (may Allah preserve him) instructs the spiritual aspirants to read Holy Quran daily. One juz (part) is usually recommended. However, if someone is unable to do this because of his busy schedule he may read half or quarter juz after consultation with the Sheikh.
If at times when even that is not possible then as per ‘Arif billah Dr. Abdul Hayy (may Allah have mercy on him) one should recite sura ikhlas (chapter 112) two hundred times in between or while busy in these activities.