Praying is our compass in the ocean of life. With prayer we maintain connection to the force that guides us. This force is always with us but with a prayer we reach out to it. Praying is our hearts talk to God.
Therefore sincerity and honesty is needed. If we pray without sincerity, our mind and heart are talking different languages, and it is always the heart that God listens.
No forms are needed. You can use a prayer taught by someone but do it with devotion. Routine does not open the door of your heart for God to come in. Only devotion and sincerity will. You can tell your sorrows and joys just as you feel them. With God no words are really needed. The easiest way to pray is just to open the heart and send your feelings. The main thing is that you reach out with your whole being. Think of God when you are crying, think of him when you are laughing.
Praying can also be taken as a spiritual practice, a way to help us remember that nothing happens without Gods approval and he knows what really makes us happy. Most beneficial praying is free from desire and full of surrender and love. When you have faith in the heart there is no need to pray for anything material. You know you will be provided everything you really need when you need it and always for the purpose of your growth.