THE FIX: Phyllo must be handled with care. The paper-thin sheets are delicate and can dry out easily, leaving you with dough that isn’t good for pastries, tarts, or anything else. Before beginning, thaw the phyllo in the refrigerator overnight. (You can store the unused portion in plastic wrap, and keep it in the fridge for up to a week.) To prevent it from drying out, work with one or two sheets at a time and keep the rest covered with a damp towel. If the phyllo tears as you’re working with it, spray the tear with cooking spray as a quick fix to bond the torn dough.