make sure we have no unconfessed sin in our hearts when we pray
pray with an attitude of humility
praying without selfish desires
pray according to his word and will, meaning that if we pray for healing, it must be scriptural.
when we submit our prayers to God we must believe and have faith only in Him, also remember that faith withought good deeds is nothing, lets make sure that our faith is at the same level with our works.
(micah 3:4, john 16:23-26, james 1:6, james 4:3, james 5:16, 1john 5;14-15, ephesians 6:18, 1 peter 3:12, isiah 59:2, mark 11:22)
I also believe that some prayers we must submit them to God through fasting (2 samuel 12: 16, esther 4:16, daniel 9:3, act 12:2; 14:23, luke 2:37; 5:33, 1 thessalonian 5;17)
it is important that we must first pray for God's wisdom so we can know the will of God, then we can be able to pray according to His will wich means praying for things that honor and glorify God and/or praying for what the Bible clearly reveals God�s will to be. If we pray for something that is not honoring to God or not God�s will for our lives, God will not give what we ask for.
if we dont know the will of God the answer is at romans 8:27.
may God richly bless u and I also believe that my comment will be a blessing to others.