I reuse leashes, toys, beds, crates, food, meds, etc.
The only thing I don't reuse really, is collars. I keep older collars tucked away, and I have two framed pictures of a foster that I had to PTS and my beagle, and the collars that they wore when they died are hanging on the frames with their tags on them. I had them hanging at my old house, but haven't gotten them out of boxes and found a spot for them here, yet.