Here is a vintage Prairie Clothing Co. pattern from 1989 for you to make a decorative sailor-style collar.
You would wear this collar with a plain shirt to dress it up. The top part of the first photo is the view from the front, and the lower part is the collar from behind.
This is a one-size-fits-all pattern.
I bought this pattern secondhand. The envelope is damaged as shown, and the pattern is uncut, factory folded, and includes directions.
Please send me any questions you may have, and thanks for looking.