This idea comes originally from a lady in Switzerland.
As you can see, the shape is very easy, and you do not have to make a drawing first.
The colors are mixed with waterbased paintingmedia ( or you can mix with oil of copaiba, just mix enough to paint the feathers).
Mix the colours you like, plus black and mixingwhite, mix in a thick consistency.
Start as showed on the diagram, and change the colours, as you work from top to the tip. Shape up with a damp brush.
Clean the small split-shapes with the brush, from outside towards the centerline.
Use a # 0 pointed brush, and paint the small dunes at the top, in a mixture of mixing white and the black, to achieve shades in light gray.The mix white will give a little relief effect.
Use the wipe-out to shape up the dunes, do it from inside and out, look at the diagram.
Wipe out the midleline at last, but do not go to very tip ....stop a bit before.
The base was painted light bluegreen, and have a netting in roman gold, and as you can see on the other box a black border with shapes of feathers.
I painted a little feather inside the box.
Colours I used: Mixing white, black, yellowgreen, bluegreen, russian green, royal blue, and olivegreen. Perhaps a bit of violet, I cant remember.
But anyway I am sure you will have fun like I did.
Regards
Birthe Hattel in Denmark.