Try sudoku. It's very rewarding to do harder and harder puzzles in just five minutes. Also, if possible, I like to step outside for a few minutes, i.e. in-betw

Try sudoku. It's very rewarding to do harder and harder puzzles in just five minutes. Also, if possible, I like to step outside for a few minutes, i.e. in-between meetings when you can't really start anything new. Breathing some fresh air, getting a bit of peace... Ah, the dream.