Now that I have had a few days of my own time in between assignments, I realize that notifications are frequent distractions that kill focus.
I suppose I have exacerbated the problem by using all Apple devices. Every message I get hit with notifications on my iMac, MacBook, iPhone, iPad, etc.
Starting with messages, I turned off the sound/vibration notifications. I left the badge notification on so that I can glance at the icon periodically and see whether I have any new messages. This has really helped cut down on interruptions.
Speaking of the badge icon, I tackled my email app next. I have a habit of keeping most messages in my Inbox, and I will glance at emails without opening them so they remain as unread. This gave me a badge counter over 3,000. This number has long lost relevance to me because I cannot keep track of how many new messages I have relative to what is already sitting there as unread. To fix this problem, I selected all messages in all inboxes and marked them all as read. Now I have a clean slate and will know exactly how many new email messages I have. I also need to be disciplined about moving emails to the correct folder, deleting them, or at minimum marking them as read.
I have made similar updates for other apps that tend to push a lot of notifications. These simple changes have reduced needless interruptions and helped me stay focused on the task at hand.