When We Don't Know What to Pray

I was recently talking with a friend about prayer, how God answers prayer, and how we should pray. A few days later, I was reading through Ephesians 1 and found yet again the beautiful prayer that Paul prayed for the believers at Ephesus.

Wherefore I also, after I heard of your faith in the Lord Jesus, and love unto all the saints, Cease not to give thanks for you, making mention of you in my prayers; That the God of our Lord Jesus Christ, the Father of glory, may give unto you the spirit of w...