Lots of the above really.
Taking an interest in their 'oh so' important rambling abouts games/youtube/memes.
(I still don't understand most of what they are explaining in great detail)
1:1 time very important even if it is just when in the car driving them somewhere.
Shared tv programs, mind don't really watch telly, but they like to watch stuff with us, things like, task master, the apprentice, bake off, robot wars. If one of them is busy when it's scheduled then we all agree a time to watch it on catch up, even if they end up lounging on our bed and watching it, as dh and me have turned in for the night.
AuntyElle ask about music, just start by finding out what they listen to. Once you take and interest and not criticise it. They'll tell more over time, then you can say things like oh that's a remake of .......or whatever.
Ds1 played one of his music play lists in the car the other day. It was great! There was dubstep, nine inch nails, Jonny cash, gorillas, The animals, bricks and mortar, some familiar recent chart songs I don't know the name of, the list was a real mix.
I'm not saying life is a bed of roses, they can still be sulky teens and kick off about stuff, and they spend a lot of time in their rooms or out. But it is nice to see them being human and wanting to talk to us.
We eat together each evening, sometimes they don't have anything to say other times they chew your ear off. 