Just pay attention to each other. Don’t take each other for granted. Show each other that you notice the little things that they do for you, for the family. Eye contact (not just picking up your eyes from your phone every so often), do things together (especially small stuff, not only fancy vacations), your words, small gifts that you know your spouse will appreciate.
Or more simply, don’t do these: Don’t look at your phone or other device when your spouse is talking to you, don’t walk away in middle of a conversation, don’t disregard their requests for your time or attention. …You see how that works…