A simple way to barbell your attention: with other people, either give them 100% of your undivided attention (no phone) or 100% ignore them.
Maybe this is even a better way to interact with your kids, or parenting. Either 100% ignore them, and let them do their own thing, or if you’re actually playing with them or engaging with them, put away all your devices and give them 100% of your undivided attention.