How should we use Biblical Psalm doxologies in worship? What is the Biblical method for their use?

Are they to be sung in worship like the other Psalms and no different then the other Psalms at different times of the service?

or

Are they to be sung at the end of each Psalm?

or

Are they to be used in singing apart from the Psalms in addition to the other Psalms?

or

Some other method?

I am referring of course to Psalm 41C, 89I, 106G, and 150B in the Psalter....