One material that I like very much to work with is  the CDC. On the market you’ll find a lot of tools that  help you work with Cul de Canard feathers.  I worked with a lot of models and types: PetitJean clips, paper clips,foam blocks  etc. but the best seems to be the Vosseler Xpert Tool Clip. I  tried this tool right  after visiting a fishing exposition. I saw this tool in the hands of a great German fly tier. He used it very easy, fast and without wasting  material.

The tool has 3 grip levels

Fixing the feathers

Cutting the barbs

Grip down the barbs

Forming a hackle loop:

Working with marabou:

Working with deer hair:

Here you can see a very good grip even for a lot of hair: