Nathan Toups on how to make your smart phone less addicting without going back to a feature phone has this closing thought:

This setup will cause you to be less responsive on chats and email, but that’s sort of the point. Your phone shouldn’t dictate to you what you focus your attention on, and the behavior it cultivates in keeping you “always ready” is unhealthy and spills over into parts of our lives that aren’t serving us well.

I’ve largely been doing this for the past 8 months now as well. The best tip I can give with the largest immediate impact is the notifications tips he gives. I mostly only allow app badges. Be careful though, you’ll want to turn off “sounds” as well, otherwise a notification comes in, makes a sound, but you see nothing and get really confused about what the fuck is going on. Anyways, I encourage you to give this a shot.