Certainly you can learn these techniques easily and practice them on your own. But for those who need the discipline of a class setting and guidance through the techniques, check into local teachers. Use your imagination. Mentally see yourself doing a task or being in a place. Visual imagery is like a dream.
Athletes use it.
Rock stars do it, too. And regular practice has been shown to improve performance. So if you use visual imagery, you may become more relaxed. Leave aside all your other activities for at least 30 minutes. You may sit or lie down.