There's a tidy little formula we can use on how we should approach God on bended knee. It goes by the acronym ACTS: adoration, confession, thanksgiving, supplication. In other words:
Let God know how great God is
Confess how bad you have been
Thank God for God's steadfast love and forgiveness, then
Hit him up for some goodies.
Not a bad approach, but it can too easily become rote and meaningless...
