"Luigi's Napkins" suggests performing a square test before you begin, practice with paper napkins, because they are easier to work with, don't rush and keep a sample or a photo of all creations. In addition, don't let logos get lost inside folds, and don't overestimate the time investment.
"Luigi's Napkins" recommends finding different folds for different shaped napkins. Some folds work better with squares, and some work better with rectangles. They also suggest finding a delicate balance of starch in the napkins, because too little causes the napkin to lose its form, and too much starch makes the napkin unusable.