The White and Blue Clouser is a great pattern on bright days. For the UK waters , a 2-3 inch length clouser has been very productive.
The clouser is tied with a dumbell or bead chain eye on top of the hookshank. When cast, the weighted eye(s) cause the hook to be reversed with the hook point upwards above the hookshank.
With most clousers, they are tied with a two colour combination. White is usually the main colour along the hookshank and the secondary colour is tied as the underwing. When cast. the secondary colour moves to the top of the fly and the white colour to the underneath.
Clousers can be tied heavily dressed with plenty of tying material or as a skinny version where hardly any material is used. Its best having a variety of dressed flies in your fly box.