Justin Taylor gives a concise overview of how Luther encouraged people to pray through the 10 Commandments (See Exodus 20:3-17). Justin then points to another link.
In A Simple Way to Pray, Martin Luther described how he uses the Ten Commandments as a guide in his prayer life:
I divide each commandment into four parts, thereby fashioning a garland of four strands.
That is, I think of each commandment as . . .
Read the rest here.