One advantage of cutting the sticks from a 16' piece of wood is that I can choose which 2' I want to cut off. Some ends are better than others.

I began my taper 5' up from the bottom - the most stress on the mast is near the bottom, so you'd want that the thickest.

I tapered the widest sticks to 2" and to get it pretty close to square, I tapered the thinner sticks to about 5/8.

Epoxy is the best glue for this, but any waterproof wood glue will work so long as you clamp everything tightly.