The Long Tail Cast On is a popular knitting technique used to create a flexible and neat edge. It involves using a long length of yarn, which is the "tail," to cast on stitches. This method allows for a smooth transition into the knitting project and is particularly useful for projects that require a stretchy edge, such as sweaters or hats. To perform the Long Tail Cast On, you need to estimate the length of yarn needed for the number of stitches you plan to cast on. A general rule is to use about three times the width of the intended project. This technique is favored by many knitters for its efficiency and ease of use.