Delete all apps that are designed to be checked over and over.
Put all other apps that could be checked over and over (finance, video streaming, shopping - believe me) inside folders, on screens behind the main screen. You should have to consciously look for them when you actually need them.
Don't sign in to any social sites in your browser, and don't let favorites or recents give you colorful icons for your frequented sites. Force yourself to type in the website you want to go to.
My home screen consists of music, direct communication, maps, notes/calendar/contacts, and the web browser. None of these can be idly checked except the web browser. They all encourage intentional interaction or none at all. Sometimes I open my phone subconsciously, look at the icons, and put it away again because there's nothing to be done.