If you have a mobile phone, turn it off.
Unplug the wall phone.
Turn off the computer and the television and the stereo.
Go in the back yard or to a window and stare at the sky for a while, say 10 minutes or more.
Don't plan anything.
Don't sort anything out.
Look at clouds or birds or stars or the shapes of the tops of distant buildings.
Don't think about anything you'll necessarily remember 10 seconds from now.