At the bottom of the heel flap is the "Turning the Heel" portion in green. This is where you make a square, round, handkerchief, or whatever heel. Since it is such a tiny section, it is easy to try all the different kinds to see which one you would like. It may be the most difficult (not really) part of the sock...but look how TINY it is!

The gusset, in blue, is easy, especially if you put markers where you are going to decrease on both sides so you don't forget to decrease every other row.

Yellow body...mindless around and around/

The toe, in orange is another series of decreases...