Tail anatomy of a Larkspur.

The tail skeleton is similar to a bird's: a highly mobile base attached to a chunk of fused bones that form the anchor for each of the tail fans.

Feather placement should be self-explanatory; the long lines at the end represent the plumes, and the shorter lines represent each of the caudal rudder feathers.

The other drawing is an attempt at the 3D structure of one of the plumes. Each half is at roughly a 120-degree angle to the other; it's a cross between a pheasant's tail feather and an ostrich plume. The barbs lack barbules on the outer halves beginning about a third from the end of each plume; therefore they look rather fluffy at that point. (The barbules are what make the barbs of a feather "stick together;" when you "zip up" a feather, it's the barbules that hook onto each other.)