Get in the habit of putting your phone down when you are in the room with your child. Don't have it on the dinner table, or anywhere you would socialize with your children. It's really best to just avoid using it as much as possible around your kids. Obviously, if you have to make appointments and stuff, that's different, but scrolling social media, reading news, etc. should be left for the evenings after kids are in bed. Kids don't really care what you say as much as they are always watching what you do.

The overall lesson for your kids should be that a phone is a tool you use to accomplish some task that takes a limited time. You turn on the phone, do the task (whether it be making a phone call, looking up an address, whatever) and then you turn it off. A phone is not a consumption/entertainment device that you sit down and just use, without a clear end state. You, as the parent, need to internalize this, and live that attitude yourself, and chances are the kid will follow your good example.

Problem is, many parents are also addicted to their phones, and won't be able to have the discipline to use them this way.