If you have knit a hat, you might want to put a pom pom on top to add a finishing touch, especially if you knit it yourself. Hand knit hats have a tiny hole at the top, and these decorations cover up that little hole. Pom poms are easy to make and attach, and are a fun way to add some interest to your hat.
Figure out how big you want your pom pom. The size of your pom pom and its thickness is completely up to you. The pom pom pictured above is a fairly large one, and it is also moderately thick.
Find a piece of cardboard or very stiff paper, and cut it to the longest length that you want for your pom pom. For example, a 2 inch finished pom pom would be suitable for a child's hat, and cutting the cardboard to 2.25 inches would be the right size for winding the yarn. If you want a 3 inch pom pom for an adult hat, cut a piece of cardboard that is 3.25 inches in length. The width of the cardboard should be 4 to 5 inches.
Start winding the yarn around the cardboard. For a thick pom pom, wind the yarn around about 200 times. You don't have to make an exact count unless you are making more than one pom pom for your knitted hat.
Cut a 12 inch length of matching yarn, and slip it through the wound yarn. Tie it as tightly as you can. A tight tie makes the pom pom appear thicker. It might help to have someone hold the knot down for you while you make the second knot.
Cut the yarn with the scissors by cutting it from the opposite side of the knot. Don't worry if it doesn't get cut exactly even. You will have to trim it anyway.
Shake the pom pom out and, using the scissors, start trimming it until all the yarns are even. Do not cut the yarn strands that you used to knot the pom pom. You will use that yarn to sew the pom pom to the top of the hat.
Thread the tapestry needle with the extra yarn that you used to tie the pom pom together, or use the crochet hook to attach the pom pom to the hat. Insert the needle or the crochet hook through the small hole at the top of the hat, and weave the yarn through the knit stitches. Take the other end of the yarn that you used to tie the pom pom together, bring it through the hole, and tie it to the end of the yarn that you used to sew the pom pom onto the hat. Make several tight knots, and trim the yarn ends.