I put my phone in "do not disturb" mode for the entire day. Removing notifications altogether was a great improvement, without getting rid of the phone altogether. You go from responding to picking it up when you decide to.
As someone who has been doing the DND mode for over 8 years now to avoid expecting notifications, it instead has taught me to reach over to my phone every 30 seconds to check the screen for any new ones :(
i've started to just chuck it somewhere if I'm trying to focus
I go through and explicitly disable notifications for almost every app. I don't really need to be interrupted to find out someone liked a photo, or that there's something in the news, or that it's raining, or that some new shit shipped from eBay. So even if I do check my phone, I pretty much only have (and then only silent) notifications for messengers. My wife and close friends know that if they need to get me immediately that they can send me a real SMS.
When I got a new phone about 6 months ago, I spent about a week horrified by the number of notifications that I was getting by default.
Same. I wanted to minimize use. The only apps that "speak" are: phone, messaging, Skype. The group chats are muted, and I also disabled the auto-refresh of emails. Now unless someone is sending a message just to me, or calls me, the phone stays silent. All other apps (gym, etc) have notifications off completely.
That, and keeping the charger in a remote corner, helps to park it and forget it.
Don't DND, use airplane mode (if you want antitheft or incoming calls, disable cellular data and wifi--prey and other antitheft can toggle data by text message if necessary). This way you've still got it available for manual use when necessary, without the wait to turn it on.
Also, disable face/fingerprint/pin unlock, and use a longish password, so unlocking it isn't convenient.