I shared a great video for Folding sheets in the past.  The 2-minute Fixology video below not only better explains how to Fold the fitted sheet (see first video for storing method), it also includes clothing items you may want to: put in a drawer, pack in a suitcase, or put on a shelf.  If you are still confused about how they did the t-shirt since they do not talk your through it, check out the step-by-step video on t-shirt folding,