I typically wear cashmere socks with my shearling boots, which are very thick. So, I sized up a half. This is my third pair of shearlings on the HOK last, and I went 1/2 up on them all. The fit is spot in on all of them for me, YMMV.
One more question.
Hok last fits me ok-ish. Perfect for the left foot, but for my right foot (my toes are thicker, normal otherwise), I feel some pinch at the big toe or the penultimate toes. The pinch depends on the time of the day, but definitely the fit is not as comfortable as the left foot.
I am size 7.5 and was thinking to go size 8 with shearling. 8uk without fur would be probably too big (especially for the left foot). The question is, does shearling take up some space or 8uk without fur feels the same as a 8uk with fur?
I am hoping that fur takes up some space and with some thicker socks I can have both legs feel comfortable without heel slip.