Thanks for linking to my thread 
I did go on to use these bones in a spell jar: First spell jar.
For me, as I said in the thread linked, I hate waste and I wanted to honour life of the bird who had passed. As part of creating the spell jar I thanked the bird for allowing me to use its bones.
I also have quite a few feathers on my altar. Some are from my own cockatiels, they shed quite a lot in the bottom of their cage, and others are from Crows and Magpies that I’ve collected on walks. I’ve also got one bright turquoise feather I picked up whether has either been artificially dyed or comes from a Kingfisher (we do have those on the stream running through my local woods). It was pretty though so I cleaned it up and it’s being guarded by my statue of Hekate.
I’ve also been using my airfryer to dry flowers and there are a fair few dried flowers on my altar as a result. I quite like including things from nature.