Write a blog post. Play through a song once or twice. Read a short poem over and over again. Memorize an extremely short text. Send a short email of acknowledgment. Read three pages of a novel. Put down on your calendar all the meetings you have next week. Shave. Make coffee. Go to the bathroom. Get dressed. Go to the office and talk briefly with a colleague. Take a five-minute nap.
Start cleaning your office. Find a book you'll need for later. Unload the dishwasher. Straighten the books on one bookcase. Dust off your desk. Water the plants. Make a to do list. A shopping list..
There's a lot you can do in 5 minutes on a low concentration day.