David's two-question prayers
The prophet Samuel told king Saul that God sought a man who was after His own heart (1Sam 13:14). That man was David. The first 5 times the Bible records prayers of David, there is an interesting pattern. He is inquiring of God by asking Him for direction and information, and he does so by asking God two questions, not just one. He heard that the Philistines had attacked an Israelite city called Keilah, but he was running for his life from Saul (1Sam 23:1-4). He asked God if he should attack the Philsitines, and God said yes. His men were afraid, so he asked God again; and again God said yes. They went and God gave them victory.
Saul heard that David was in Keilah and headed there to kill him (1Sam 23:9-12). David asked God 2 questions: will the men of Keilah give him to Saul, and will Saul come for him? God said Saul would indeed come. David asked again if the men of Keilah would betray him. God said they would. This is interesting for 2 reasons. You would think after David had just risked his life twice over for these people they would be a little more appreciative; but also, David asked until he got the answer he needed.
Later, Ziklag, the city David and his men were living in at the time, was invaded while they were gone. Their families and their possessions were all taken. David again prayed a 2 question prayer. He asked God if he should pursue the invaders, and then he asked if he would overtake them (1Sam 30:7-8). God told him him to pursue them because he would doubtless recover all, and he did.
After Saul died and it was safe for David to return to his homeland, he asked God if he should return (2Sam 2:1). God said yes. Then David asked which city he should go to. God said Hebron. That became David's headquarters for the next 7 years.
Lastly, after David became the king of Israel, the Philistines came against him. He asked God 2 questions" should he go against them, and would God deliver them into his hand. God said yes to both. There are other recorded prayers of David (2Sam 5:22-23, 2Sam 7:18-29, 2Sam 12:16, 2Sam 15:31, 2Sam 21:1, 2Sam 24:10, and in the book of Psalms). It is reasonable to assume there were many other unrecorded prayers as well (Ps 22:2, Ps 55:17, Ps 63:1).
So what can we learn from David's 2 question prayers? First, we see that David had a pattern of always seeking direction and information from God before acting. He "served his own generation by the will of God (Acts 13:36)." It also shows he was not content with only some information on what God wanted him to do. He wanted to get it all right. He would pray until he knew the full will of God for him. Some people are content to get a few pieces of information from God, or to get a general sense of direction. Others want "that good, and acceptable, and perfect, will of God (Rom 12:2)." God has a specific, individualized plan for each of us, but it is up to us to seek to know what it is and do it.
Some people pray very generalized prayers. Reasons for this include a lack of desire or commitment to do exactly what God wants, a lack of knowledge of the scripture and therefore of how to pray according to the will of God (Mt 6:10, Lk 22:42, 1Jn 5:14), and misunderstanding of the need to pray specifically. If you want generic answers, pray generic prayers. If you want specific answers, pray specifically. God can do it. He made the universe with great complexity and detail. The tabernacle in the wilderness was an example of the pattern of things in heaven (Heb 8-10). It was very detailed. We should leave room in our prayer life for consideration that our knowledge is limited and God's is not. We do not always know what God is doing in every situation. God gives us the Holy Ghost and praying in tongues to help us pray correctly when sometimes we don't know what to pray (Rom 8:26. 1Cor 14, Jude 20). That is not to avoid praying specifically, but to help us pray beyond human understanding and power the specific will of God.