The shuttlecock cdc trout flies work best in flat calm or light ripple when buzzers are hatching but worth trying when there is no surface activity. Try Suspender Buzzer first and if that does not work then the fish probably want the buzzer slightly higher so use the Shuttle Cock trout Flies
We usually use a fluorocarbon tippet as it is clear and slowly sinks but does not usually pull the fly under. It leads to a neat presentation. Always change the shuttlecock fly after a catch as the cdc fibres will have clogged together. Let the shuttlecock fly dry naturally in your waistcoat fly patch. Never grease the fly as the cdc gives loads of buoyancy and floatant will clog the cdc and the fly does not fish properly.