Music. Headphones. Chillstep, progressive, chillout etc. from di.fm. Long mixes from SoundCloud with and without vocals. "Instrumental"
Breathe in through the nose and out through the mouth.
Less sugar and processed foods. Though everyone has a different resting glucose level.
Apparently it's called alpha-pinene.
Fidget things. Rubberband, paperclip.
The Pomodoro Technique: work 25 minutes, chill for 5 (and look at something at least 20 feet away (20-20-20 rule))
Lists. GTD. WBS.
Exercise. Short walks.