Ok so here is the link to the sketch of the cycling shoe. I actually did this sketch right after the one I posted here (when I saw the invitation to do a video). Its a little sloppier but shows how I work digitally.
Notice there are a lot of control Z’s in there. I like to just throw down quick sketches and sort of mold out the form as I go. I didnt for this sketch…but usually I will overlay this line work on another layer and clean up!
Hope this helps!..video is about 11 min.
Turn on music of choice while watching…Mine is “danger zone” from Top Gun 
…jk