Perhaps adornment was a poor choice of words.
Maybe personalization is better.

One shooter had "smiley face" stickers on the end of his magazine tubes.

Another has his last name on a label placed on the fore-end cap.

I jokingly told my nephew I thought a pine tree air freshener dangling from the mag tube would be nice.
He said that would help, but only if he was down wind.

Thinking about wrapping the lever with some buckskin I had tanned from a whitetail.