Choice items, including egret's head feathers (6)
I believe the answer is:
plumes
'feathers' is the definition.
(I know this)
'choice items including egret's head' is the wordplay.
'choice' becomes 'plum' (both can mean excellent).
'items' becomes 's' (I can't justify this - if you can you should believe this answer much more).
'including' indicates putting letters inside.
'head' says to take the initial letters.
The first letter of 'egrets' is 'e'.
'plum'+'s'='plums'
'plums' placed around 'e' is 'PLUMES'.
Can you help me to learn more?
(Other definitions for plumes that I've seen before include "Clusters of feathers for display" , "Fancy feathers" , "Curling columns of smoke" , "Clusters of feathers worn as ornaments" .)