There are many prayers already written that are beautiful and you can certainly use them to pray to God. But I still believe that the Lord loves to hear prayers that come directly from your heart. Only you know your own feelings and thoughts best, so prayers formed by you in your heart speak most intimately to the Lord. You don't even need to be concerned about correct grammar, proper wording, or how fluent or clumsy you are ... just thinking about your intention is good enough for the Lord to know. The main point is to let him see the genuine you. Keep sharing yourself with him like this and you will hear from him and develop a most intimate relationship with him. Then you will experience his holy presence. Naturally, receiving him in Holy Communion can greatly expedite this process. In sum, open up to God to let him open up to you.