Take the time to arrange your physical environment for a minimum of distraction. Hide or close browser tabs, icons or extensions. Uninstall any unused apps. Clear your desktop and desk of unnecessary items and mess, sort things into the appropriate folders or drawers, store them somewhere, or trash them.
Photographs, empty coffee cups, etc., take up space in your thinking, perhaps moving the photographs to a bulletin board behind you will keep them where you can see them when you intentionally want to as a refresher or mental break, will be beneficial. And when you are done with your coffee, take your cup to the sink, wash it and put it away.