"Most Christians for most of the Christian centuries have learned to pray by praying the Psalms" writes Eugene Peterson in the Introduction to Psalms (NavPress, 1994).
He goes on to describe the difficulties a lot of people encounter when trying to pray and with trying to find the right prayer "language". "Faced with the prospect of conversation with a holy God who speaks worlds into being, it is not surprising that we have trouble ... Untutored, we tend to think that prayer is what good people do when they are doing their best. It is not. Inexperienced, we suppose that there must be an 'insider' language that must be acquired before God takes us seriously in our prayer. There is not. Prayer is elemental, not advanced, language. It is the means by which our language becomes honest, true and personal in response to God. It is the means by which we get everything in our lives out in the open before God."
He goes on to say: "In English translation, the Psalms often sound smooth and polished, sonorous with Elizabethan rhythms and diction. As literature, they are beyond compare. But as prayer, as the utterances of men and women passionate for God in moments of anger and praise and lament, these translations miss something. Gramatically, they are accurate. The scholarship undergirding the translations is superb and devout. But as prayers they are not quite right. The Psalms in Hebrew are rough and earthy. They are not genteel. They are not the prayers of nice people, couched in cultured language."
From my own experience there was a major change in the way I prayed which started about 7 or 8 years after I was baptised, when I was in my early twenties. I was praying one day when I suddenly realised that someone was listening - I was aware of the presence of God for the first time. Until then I had struggled with trying to find the right kind of language for my prayers, which were often formal, structured and polite. I addressed God as "thee" and "thou" and used Jacobean language as best I could (which meant saying things like "dost" instead of "do", "seemeth" instead of "seems", etc). I had been raised on the King James Bible, so I had a pretty good handle on the archaic English, but it somehow made my prayers feel irrelevant to real life.
I began to pray conversationally, to speak with God as though He was right there beside me, listening (He was!) The more I did this the more I became aware of His constant presence, and so the more I talked with Him. Instead of praying at set times, I began to talk with Him whenever and wherever I wanted to. Conservations with God became part of whatever I did - my work, entertainment, friendships, and all of life. In time I became aware that not only was God always present, He was also with me as my friend. I learned that I could talk with my friend about absolutely anything! After all, He knew about everything that was going on in my life because He was there, so why not talk with Him about it? I discovered that nothing was taboo; there was no subject about which I could not talk with God.
This realisation lifted a huge burden from my shoulders. I did not have to carry anything alone. God would never abandon me, or refuse to listen. From the Psalms (especially, later, in Eugene Peterson's translation) I learned that we could tell God exactly how we felt, even when what I was feeling was not necessarily "holy" or Christian. If I felt angry, I could tell God (even if I felt angry with God!). If I was finding it hard to pray, I could talk with God about it. At the times when I wasn't feeling "spiritual" God wanted to hear about it.
So, if you're having trouble praying, I would recommend you get hold of a translation of the Psalms like Peterson's (The Message) and see how others prayed with "raw honesty and detailed thoroughness", and then do the same. Forget about using some archaic language, and just talk with God in the same language you use with everyone else, everyday (the same as Jesus did - the language He used for prayer was the same language He used in the street. Hebrew and Greek did not have a special way of addressing God. "Thee" and "thou" as terms for God but not for anyone else, is a late English religious peculiarity).
Remember, Paul says "pray continually" (1 Thess 5:17) and to pray about everything (Phil 4:6). Start with short prays, and often, rather than trying to fit it all in one long prayer. Pray as things come to your mind rather than trying to remember them later at "prayer time". Tell God how you're feeling, whether it's good or bad. Tell Him why you feel that way. Tell Him how you want to feel. Thank Him for every good thing that comes your way, not matter how "unimportant" it might seem (thank Him for when you find a parking space in a busy shopping mall; thank Him for the phone call from a friend that comes just when you're feeling lonely or down; thank Him for the friendly smile someone gave you in passing; thank Him for the sunset that just makes you want to say "wow" and make it "wow Lord!).