Abu Darda (radiAllahu anha) relates that the Messenger of Allah (salAllahu alayhi wasalam) said, "Whoever performs ablutions well and offers two voluntary rakahs and completes them to perfection will be granted by God whatever he prays for, either immediately or in God’s good time."
[Ahmad - Sahih]
Abullah ibn Abi Al-Awfa Al-Aslami (radiAllahu anhuhim) relates that the Messenger of Allah (salAllahu alayhi wasalam) said, Whoever has a need with Allah, or with any human being, then let them perform ritual ablutions well and then pray two rakats. After that, let them praise Allah and send blessings on the Prophet (salAllahu alayhi wasalam). Then recite the following dua:
[at-Tirmidhi, an-Nasa'i and ibn Majah]
The hadith has some weakness, but it is slight: such hadiths are acted upon for virtuous deeds (fada'il al-a'mal) by general agreement of Sunni scholarship