When you lie down with a short prayer, commit yourself into the hands of your Creator; and when you have done so, trust Him with yourself, as you must do when you are dying. ↗
Perhaps one of the only positive pieces of advice that I was ever given was that supplied by an old courtier who observed: Only two rules really count. Never miss an opportunity to relieve yourself; never miss a chance to sit down and rest your feet. ↗
You're trying to put yourself in that moment and trying to prepare yourself, to have a 'memory before the game. I don't know if you'd call it visualising or dreaming, but I've always done it, my whole life. ↗