My teens had interaction with us over breakfast every morning - we chatted as I made breakfast and packed lunches for them and every evening as we had dinner together and discussed our days. They chatted with their dad if he drove them to or from school (which was fairly often as the trains were unreliable) and to both of us as they were driven to and from parties and sports fixtures. We went for walks every weekend and chatted all the time on those. We went to galleries, theatre, museums, opera, comedy shows, restaurants, Go Ape, amusement parks, old steam fairs, kayaking, cycling, hiking, mountain climbing.
We had silly rituals like doing a quiz from the weekend papers over lunch; we did family film nights with pizza on Fridays, we invited their friends over for bbqs and sleepovers and teenage parties. We tested them on revision for GCSEs and researched unis with them. We planned holidays together, taught them to cook, to build flat pack furniture, to tidy and clean. If they were upset over fallouts with mates or first loves, we were on hand with ice cream and comedy reruns. If they felt ill we ran them baths and made specific foods they craved, checked in on with hugs. If they had bad grades we discussed how to improve them. If they felt inadequate in comparison with friends, we helped them gain perspective and feel good about themselves.
They shared tech knowledge with us and introduced us to new music, new idioms, great films, food, jokes and comedians. We recommended books to each other. They explained points of view we might otherwise have dismissed. We argued about politics and language and economics and philosophy. When we were tired or ill they'd care for us. When I had to sort out my dad's funeral I came home to discover DS2 had tidied my study. Another time, when I was very busy at work, DS1 cleaned the house as a surprise. And both of them at different times surprised me by taking me out for dinner, using their allowance.
None of this was forced. It's just how we muddled along together for their teen years. I wouldn't have missed any of that for the world.