The heels are on, more or less. I'm not sure if they are centered, since you aren't supposed to try on your shoes at this point.  The chalk outline I used to line them up is still visible, as well as flecks of debris all over the shoes. I'll be happy to get to the point where I can clean them and see what they really look like.

Skiving is shaving the edge of the leather to a thin dimension in order to reduce bulk.  It can be done with a special skiving knife, or if you are on a budget, it can be done with a utility knife as explained here.

I chose the utility knife route since I had one, and practiced on scraps.  I thought I had it, but then, of course, gouged a chunk out of my sole on the first go. I think it's fixable, though.

I finally got the hang of it, and took a nice, long, smooth cut off one side, then immediately started having problems. The knife wasn't cutting anything and I realized it was dull.  My knife sharpener did a good job of bringing it back to working order and I had to sharpen it once more before I was done. Leather is hard.

I think I'm done for today because my hands are a little numb and I still need to play my harp!