Put them in water or take them outside. This is the best parenting advice I’ve ever been given. When breastfeeding has been established (baby is making good wet and dirty diapers, generally pain free latch, and gaining weight), there will be times when baby will be super fussy and refuse the boob. Many misinterpret this as having low milk supply or something wrong with the breast. Don’t be so quick to blame yourself or to supplement with a bottle. I guarantee you there will be times when you have no idea what to do to stop your baby from crying. The boob won’t work. Changing the diaper won’t work. Burping and rocking and shushing won’t work. I guarantee you there will be times when you will cry right along with your baby and feel helpless to soothe them (or yourself).
When the breast doesn’t work: put them in water or take them outside. It works. When your baby is falling to pieces for no apparent reason and the usual tricks don’t work, go outside or get in water. It works on adults, too!!