Knitted hats are easy to knit in the round or to knit flat and then sew up, but you may be confused about how to close them. Most hats are knitted from the top up, and when you get to the top, you need to close off the tube that you have created. When closing the top of a hat, you do not need to bind it off. Once the tube part of the hat has been knit, decrease the stitches on the needles according to the knitting pattern and then close the top.
Cut off the yarn, leaving a 12-inch-long tail trailing from your project.
Thread the end of yarn through a large yarn needle.
Push the end of the yarn needle through the loops of yarn still on your knitting needle, pulling them off the needle and onto the yarn needle as you do so.
Pull the length of yarn through the loops, cinching the top of the hat tight. At this point, the top of the hat is closed, and you can use the remaining tail of the yarn to sew up the hat, or you can pass the needle several times through the hat to secure it.