Inspired by some wall hangers I saw on thingiverse, I realized these where not what I needed. So I created my own.
The grommet slips on the hook and is self centering and self attaching to the wall because of the slopes I added.
The picture shows all three versions I did, dark gray in front is the final version v3 I use to hang pictures. v2 was already good, but to help in positioning the grommet at the center of the frame, I also added a sunken marker for the center.
The author marked this model as their own original creation.