Customs and Manners of Making duas and the Causes for their Being Answered:
1. Faithfulness to Allah
2. To start with thanking Allah and praising Him and then giving salat on the Prophet (SAW) and ending the dua with the same.
3. To be serious in dua and certain that it will be answered
4. Persistence in the dua and not rushing it (Hadith says don't rush or be impatient. Don't say "I prayed for such and such a thing and Allah didn't answer my prayer. Allah dislikes that.)
5. To put your heart into the dua -- make it from your heart (even if you are reading the words, i.e., mean what you say)
6. Say dua in times of crises as well as times that are good -- don't just say dua in times of need only.
7. Ask Allah alone -- and no one else.
8. Do not make dua on someone's family or money or child or life -- that is, don't say I wish that that person's family be destroyed, or I pray that she loses all her money, or I wish his oldest son would fail or I wish that he would die.
9. Make dua in a moderately low voice -- not silent yet not completely out loud.
10. Know your sins (faults) and seek forgiveness for them and know and acknowledge the benefits and blessings you have been given and thank Allah for them.
11. The oppressor should make amends for what he has done and repent.
12. Turn to Allah with humility, desire and fear of Him.
13. Do not use rhymed prose when making dua.
14. The supplication is (said) three (times). [Hadith that states that the Messenger of Allah (SAW) when making dua, repeated it 3 times.]
15. Face the Qiblah when making dua.
16. Raise the hands during dua [sunnah, not wajib]
17. Make wudu before making dua when possible.
18. Don't pray for injurious or harmful things to happen to people (like praying someone has an unfortunate mishap, or falls down, or chokes or breaks his leg, etc.) Also remember, that the Angels say "Ameen" and the same for you," after your dua.
19. The person making dua should start with himself if he is going to pray for someone else.
20. To make intercession to Allah by use of His beautiful Names and superior Attributes, or by some good deed that the supplicator performed or by the dua of a good man living, who is in his presence (e.g., asking someone who is a good Muslim to make dua for you)
21. That the food and drink and clothing is halal and of a halal source
22. Do not make dua for a sin or cutting off of family ties.
23. To order that which is good and forbid that which is forbidden
24. Distancing one's self from all types of sin.
