I think it is safe to say that for pastors, our Lex Credendi drives our Lex Orandi. In other words, what we believe informs and influences how we carry out our ministry. When planning and conducting the Divine Service, we pick certain hymns and use certain ceremonies based on what we know to be true about God, Christ, Sin, Grace, The Sacraments, etc. Our doctrine, our Credendi, drives our practice.
For the person in the pew, for the one on the receiving end of the liturgy, it is the other way around. A person believes as he is given to pray. His doctrine is only as good as his hymns and liturgy, assuming that the person does not do a vast amount of theological reading and study on his own. For the average Christian, I think it is safe to say that their faith is formed more by their Orandi.