The greatest reasons for having one's Du`a' answered are: Taqwa (fear/wariness of offending Allah). Allah (Exalted be He) says:
Verily, Allâh accepts only from those who are Al-Muttaqûn (the pious).
Food, drinks, and clothes should be from lawful income. It was authentically proven that the Prophet (peace be upon him) said to
Sa`d (may Allah be pleased with him)
"If you earn your money lawfully, your supplication will be answered."
Among the reasons for having the Du`a' answered are: raising up the hands, paying great attention to the (Part No. 2; Page No. 218) times and places when Du`a' will be answered. On the other hand, repeating the Ayahs (Qur'anic verses) mentioned in the question is not a condition for answering the invocation, it is an act of Bid`ah (innovation in religion).May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.