My advice to fathers-to-be: work smart and hard leading up to birth, build as much momentum in your meditation practice as possible, strengthen your back muscles (never skip leg day), expect to get 3x less done after birth, take time to ground your nervous system daily, and remember your primary job in the early days is supporting the mother.
I once read in a parenting book that one way to deal with kids’ tantrums is to “parent with awe.” In Hunt, Gather, Parent, Michaeleen Doucleff observes the way some Inuit mothers are able to calm children by encouraging them to turn their attention toward beautiful, worldly things.