I had purchased the Haute Decor MantleClip Stocking Holder Rod from Amazon and was not impressed by their included hooks. It kept on falling off the mantle and did not sit right with the smaller / extended part of the rod. I designed a quick replacement that has far exceed my expectations. I went through a few revisions, but it sits well and would probably work for a lot of mantles out there in newer homes.

https://www.amazon.com/gp/product/B01MDTKZY9