May the LORD answer you in the day of trouble! May the name of the God of Jacob protect you!  May he send you help from the sanctuary and give you support from Zion!  May he remember all your offerings and regard with favor your burnt sacrifices! Selah  May he grant you your heart’s desire and fulfill all your plans!  May we shout for joy over your salvation, and in the name of our God set up our banners! May the LORD fulfill all your petitions!  Now I know that the LORD saves his anointed; he will answer him from his holy heaven with the saving might of his right hand.  Some trust in chariots and some in horses, but we trust in the name of the LORD our God.  They collapse and fall, but we rise and stand upright.  O LORD, save the king! May he answer us when we call. (Psalm 20 ESV)
Prayer for Planning
Now we see the prayer of the people on behalf of the king that his heart’s desires would be met (assuming those desires are in line with a ferocious love for God, Psalm 37:4), and that all of his planning would be blessed by the Lord.
In our culture, many Christians think that planning means that you don’t trust God. Quite the contrary is true in the Scriptures when you see people like Joshua and David using their God given talents of organization and strategy to advance in military conquest. Or like Nehemiah, Solomon and Joseph who organized whole nations into productive, prosperous people. Planning isn’t evil unless the plan is to disobey God. That’s a bad plan. The people here are praying that God will bless the plans of David as he advances the kingdom of God.
We too should pray for one another and for ourselves that God will give us wisdom as well as others and that all our plans will be aimed at God because our desire is to genuinely please him.