When showing the turned hat brim that C knit, I mentioned that it requires a provisional cast on. One of the simplest provisional cast ons begins with a crochet chain (see photo above) using waste yarn. One crochets a chain that is at least 10 stitches longer then the number of stitches that one needs to cast on. The red arrow points to the loop that remains when you remove the crochet hook. Important to mark that loop, I tie a knot in it.
The red arrow points to the knot tied in loop. This is what you undo when one is ready to pull out the provisional cast on.
The blue arrow in the photo points to the bar that one finds on the chained stitches. This bar creates the stitches. Insert the needle under the bar and knit off, using the working yarn. Knitting the new stitches using the bar of the crochet chain can be a bit fiddly. The photo to the right clearly shows two stitches that have been knit with working yarn (red/green in color) and the needles are in the middle of creating the third stitch. If you look at the chain of stitches below the needle points, one clearly sees the "V" of the crochet chain. (blue arrow in the photo below) This is generally considered the "right" side of the crochet chain. The bar used in the provisional cast on is on the "wrong" side. When you begin the provisional cast on, always begin 4 or 5 chain stitches from the end.
This is how the stitches look once cast on,. Begin the first row by continuing with the working yarn.