Step 1: Cut Out Pattern Pieces
Print out pattern and cut out.
To save time, fold your fabric in half so that you are cutting out two pieces instead of one.
Place on polar fleece and cut out pattern.
I cut mine free form and just held the pattern down, but it might be a better idea to pin the paper to the fabric first.
Note: Before cutting decide if you want a hat brim that is stretchy or one that fits more precisely. If you want a stretchy brim, which I recommend, pull on your fabric to figure out which way the fabric stretches. Once you've got that place your pattern along the direction of the stretch.
If you don't want your brim to stretch place it in the direction the fabric does not stretch.