Here is how you can make a Santa hat for Christmas using felt. The same technique can be used to make Christmas hats using other types of fabric.
Glimpse of the Result:
Take a square sheet of thin felt cloth.
Shape it like a cone with the good side of the cloth going inwards.
Make stitches to join the two ends of the cone. While stitching, leave a small gap at the top part of the cone.
Bring the inside out.
Take a strip of white felt and stitch it along the bottom of the hat. Hem the lower part of the white strip to make it neat and even.
Now take a smaller square sheet of white felt cloth. Place a ball of cotton at its center and wrap the cotton ball with the felt cloth.
Attach the ball of covered cotton by inserting it in the gap on the top of the cone. Make a few stitches to secure it.
And with this, the santa hat is done. You can make embroidery on this or add any other design for an enhanced look.