I always say "finish the 1st breast breast first, then if baby seems to
want more offer the 2nd for dessert."  This usually works well for the
first week, for most babies.  I also tell parents that by the end of the
first week, most babies are giving cues that they need the 2nd helping  and
dessert!  My clinical observation is that most babies nurse very well on
one side in the first few days and then zonk out and do not arouse easily.
If the first breast access is limited by mom, they usually won't take the
offered 2nd side.  People seem to come with the notion of "must use both
each time" OR "must only use one each time."  Nobody watches the baby!
Ack!  Sincerely, Pat in SNJ