I always thought everyone added hanging loops to their towels but apparently not! I cant take responsibility for the idea, i copied it from my sister but we've both done this for years so i thought i'd share.
I love it when a towel comes with a built in hook but they rarely do these days so i always add one myself.
Its just a small lenght of ribbon folded over and sewn in place. Pin it first to make sure its in the right place.
Then sew backwards and forwards over the ribbon a few times as it'll need to be strong. You can do this by hand, just make sure its nice and secure
The ribbon ends will fray, especially after youve washed it a few times. You can seal the end with nail varnish but i never bother, it is just a towel after all!