Step 1
The first step depends on two conditions: one, the thickness of the yarn and, two, the size of the person's head, whom you are knitting the hat for. Based on these, the needle size should be decided, which is simple, bigger the head or thicker the yarn, bigger the needles. The standard size is U.S. 7 or 8. If knitting for an adult, you can use these to easily work with wool yarns. For a kid's hat, size U.S. 5 is the best.