George Buttrick gives some clear "hints" on prayer, warning there are no binding rules. His intervals of prayer (Thanksgiving, Confession, Intercession, and Petition) are not unique, but they help me practice prayer.
Buttrick challenges us to be specific in our individual prayers. Examples:
"If we are 'thankful for everything,' we may end up by being thankful for nothing."
"Genuine love sees faces, not a mass: the good shepherd 'calleth his own sheep by name.' Intercession is more than specific: it is pondered: it requires us to bear on our heart the burden of those for whom we pray."
I was encouraged by, and grateful for, this book and his thoughts on prayer.