A buzzer really looks good with a clear glass bead to imitate the bubble on a rising pupae, and with a fringe of cdc to imitate the gills.
It is not easy to thread or pull the cdc through the bead, so this is how I do it.
First, put the bead on the hook and move it out the way.
Then put on your stacked cdc feathers using a thin thread like griffiths 14/0
Secure the CdC with as few turns as possible, tie off on the hook shank and cut thread.
Now slip your bead over the tied down feathers, and put a drop of glue behind the bead so that it wicks up into the bead and secures the CdC properly.
Be careful not to use too much glue
Then continue with the rest of the fly