The most significant gift I have been given is learning to pray. Not that you can pray wrongly, but understanding how God hears your prayers is a gift from the Lord.
Powerful prayers are those that you are grateful for having what you have not seen come to pass. For example “Father God thank you for the joy you bring to my life, I enjoy a happy faith-filled life” even if this is not yet come to pass. Let God know you’ve received it and grateful.
When you pray in faith, I can tell you from my own experience it works. Pray as though something has already come to pass. 
One important note about prayer. Don’t beg God. You don’t have to beg God for him to hear you. If you have a sick child or loved one. We tend to say “God I’m begging you” this is not necessary. God is a God of love, he does not need you to beg. Go to him with a faith-filled heart and see what his grace will do in your life.
God moves by faith in him. You live your life in hope and rest, let God do the rest. He has taken a terrible season in my life, teaching me that if I’m faithful in faith, I can find peace. Not just peace but miracles, blessings that are far beyond my imagination.
Try earnest faith-filled prayer, it will change your life. I’m grateful beyond words for what prayer
What you wrote here: “Powerful prayers are those that you are grateful for having what you have not seen to come to pass.” really spoke to my heart. Thanks for posting this.
Thank you and god bless!