First of all I want to say thanks for taking communit suggestions, So here is what I will suggest.
From the list shared in this blog i think the neck locket will be a nice one for sure and apart from that small hairs can come with a Band while long hairs can come with different hair styling.
My personal suggestion will be to add wings and make a angel like avatar for female charcters that can also come with some in game benefits apart from the look. So I would love if wings could be added as well.