I start with a square approximately 5 by 5 mm. Each crane takes about 45 minutes to fold if I'm very focused and accurate, but I still occasionally fail and need to start over from the beginning, which can be frustrating. For the most part, I use my fingertips to roll and press the paper into position, which requires sight and touch sensitivity in combination. Then, to make the folds sharper, I use a surface like a table and my fingernails. When folding, at times, I'm holding the paper with just my fingernails. The most important thing is to be very precise when laying the initial folds. Even half a millimetre of inaccuracy can affect the end result dramatically. Also, don't handle the paper too much, especially with moist or sweaty hands, or the paper will get mushy and the folds won't react properly. I often let the paper rest and dry for 30 minutes after making the first 16 folds. Though it can be exhausting and time-consuming, I find the process meditative, challenging and super satisfying.