Hebrews 4:12 says that God's Word is alive and powerful, sharper than a two-edged sword. When we speak and pray the Scriptures, we are coming into agreement with God, and His power is released to answer our prayers. Praying the Scriptures will increase your spiritual growth. You actually learn what God says about certain situations, and by praying His Word you will see His results.
When praying Scripture, you are verbally acknowledging your agreement with God and calling on Him to act in a ways that is consistent with His Word (which He always will!). It's easy to pray Scripture simply as you read or quote from memory specific verses and passages in the context of your conversation with God. For example, "Lord, just as you instruct in Hebrews 13:5, make sure that my 'character is free from the love of money, making me content with what I have.'"
Here are a few more examples:
Ephesians 3:16-19. "Father, we pray that out of your glorious riches you may strengthen us with power through your Spirit in our inner beings, so that Christ may dwell in our hearts through faith. And we pray that, being rooted and established in love, that we may have power--together with all the saints--to grasp how wide and long and high and deep the love of Messiah is. Lord, we want to know of your love that surpasses knowledge, so that we may be filled to the measure of the fullness God."
2 Thessalonians 1:11-12. "O Lord, we pray that you may count us worthy of your calling, and that by your power you may fulfill every good purpose we have and every act prompted by our faith. We pray this so that the name of the Lord Jesus may be glorified in us, so that we might be glorified together with him, according to the grace of God and the Lord Jesus Christ."
Colossians 3:15-16. "Lord Jesus, may your peace rule in our hearts, since as members of your body we were called to peace. Give us a thankful instinct and disposition, Lord! And may your word dwell in us richly as we teach and admonish each other with all wisdom, and as we sing psalms, hymns and spiritual songs with gratitude in our hearts to you."
Now, open your Bible and infuse your prayer with God's Word. Some great passages to begin with are Ephesians, Colossians, and 1 Peter.