Some things that come to mind for us:
We sing together in the car or randomly during the day.
We play games together (board games, card games, and once a week the kids play video games together).
We garden and do yard work together, never just one person doing the work.
We get outside in nature together – it may be the back yard, it may be going to the arboretum, a park, or elsewhere.
We go places together (free or that we have a membership to) – the zoo, the science center, the library, the art museum, the grocery store, church, free days at various places.
We do projects together at home – from simple things like a cleaning project to rainbow loom creations, painting/art, drawing, watching a cooking show and then getting in the kitchen together, or working through a tv or movie series like Road to Avonlea or Gummi Bears. We’ve painted rooms together. Cleaned the attic or basement (making a tornado shelter area).
We cook together. Bake together. Clean together.
We read aloud books together.