Here is a quick tutorial on binding in the round. You can use any folded neckband measurement from my patterns as a guide for binding in the round if you prefer this method over the other one.
1 - Fold the binding right sides together and sew with 1/4" seam allowance.
(I used my sewing machine because I wanted to be able to split the seam allowance for less bulk when topstitching)
2 - Pin in quarters around the neck with the right sides together. As you sew it on, stretch the binding so it's flush with the neckline. Make sure you don't stretch the neck of the garment, only the binding.
Should look something like this once it's turned right side out!
3 - Press and fold the binding over the seam allowance and pin or clip. Make sure the seam allowance is folded up and the binding is laying nice and flat over it.
4 - Topstitch using a coverstitch, twin needle, zig zag, or your go to stretch stitch on your machine. Press again if desired and you're all done!