You can do visualizations during breaks at work, at home, as you go out into nature, when you are in a bus or on a plane. But don’t do them while driving or operating machinery. Sit in a chair or just lie down with a light blanket to keep yourself warm as your body temperature drops down during visualization. Listening to soothing music can enhance your experience. Before you start, loosen your belts if you’re wearing them and take off your watch and glasses (if you can). Your visualization can be as short as 5 minutes or as long as 20 to 30 minutes.
(Shapiro Eddie & Debbie Shapiro, Peace within the Stillness,1998, pp. 101, 104-105)