As hosp LC for 5 years I found finish 1st br first was most appropriate in
early days. By end of first week baby is usually signalling that "I'd like
2nds", after finishing 1st br.  I think a rule like "use both br each
feeding" only suceeds in frustrating mom, trying to offer 2nd br to totally
zonked out baby.  One side per nursing seems to be the norm for most babies
in first few days.  Dr. Woolrich says the rule is -there are no rules.
Teach the mom feeding cues.  Tell her what we generally see (one side per
nursing first few days, changes to both by end of first week).  Then tell
her to respond to how her baby acts.  Same problem with "nurse every two
hours".  Some newborns don't!  I also tell moms that sometimes we want a
MEAL and sometimes we want a SNACK and sometimes a little dessert.
Flexibility is my motto.  She needs to know signs of adequate intake and
then relax.
Pat Young in SNJ, USA