To soothe the baby the author forgot: 1) pacifier. Holy hell those things are life savers. As my kid got older he would sometimes lose the pacifier in his sleep and start crying. We just bought 10 of them and sprinkled them theoughout his crib at night 2) driving. Driving your kid around will often soothe them. I had a particular route I would take down the highway that would guarantee put him to sleep.
https://www.mayoclinic.org/healthy-lifestyle/infant-and-todd...