Prayer is simply speaking to God. It is not some magical formula to obtain what we want, or ritual we need to practise in order to impress or score points with God.
As in any relationship with someone we love, communication with God is vital and based on a variety of different ways of communicating. This includes listening and sometimes just enjoying being in his presence without even saying a word. We don't communicate in order to try and manipulate or get our own way, but in the first place to express our love, adoration and gratitude to the God who created us as an expression of His love.
Paul mentions that we shouldn't be anxious about anything but in every situation bring our prayers and requests to God with thanksgiving (Phil 4:6).