The most effective solution I found was keeping my phone in my backpack instead of my pocket. When working I keep it somewhere I’d need to get up to get it.

Together with taming notifications this provides enough friction to discourage me from reaching for it at every spare second.

Once the phone reaches my hands the tricks in the post are not enough to remove the need for conscious effort to let go of the thing and put it back in its inconveniently positioned place.