Hi Karrie
What I did there was to lay down a bit of a tonal value over the entire area, just enough so that I could erase into it so don't press hard when you do.
I then followed the pattern on the beanie and erased it using a Tombow pen shaped eraser. (Little upside down V's)
I then used a 6B pencil the darken the areas between the erased lines. This gave a flat hat.
To make it look like it rounded I used my cloth and graphite dust to run a shading over everything left to right a little distance off the bottom of the beanie and one on the edge fading upwards.
I hope that helps.