Size is measured around the widest part of the foot. It is best done when the foot is on the floor. If the person you are making the sock for is able to, get them to draw around their foot, this enables you to try the sock on even when they aren’t there, also allows you to see when to stop for the toe shaping.
I haven’t given’t a specific yarn as it doesn’t matter so long as there is some nylon in it. I used a merino/ nylon mix for mine.
Stitch markers were made for me by my daughter you can find her on Facebook at Jessie’s crafty hands.
I also haven’t used Kitchener stitch or wrapped stitches to make it easier for all.
If you do have any questions please feel free to message me.