The skill level required using this method is relatively low. A more challenging option would be to do this only using hand-tools.
Take nothing for granted and keep safety as the most important aspect of the project. Make sure you are comfortable with the use of all the tools you use.
Step 1: Overview
Making the Boken
Notes & Cautions
I suggest that you borrow or buy a boken before you start, so you can get the feel and see the details of what you are making. It will also help you set up the curvature of the one you create. Hopefully you are already training with one at some level, so you have an understanding of the balance it should have.
Ganbate kudasai (Japanese for good luck)
Step 2: Basic Dimensions
Make the bowed shape by gluing two pieces of wood together, clamped in position.
Step 3: Ripping the Wood
Joint one of the 1-1/2 inch sides of each for to make a smooth gluing surface.
The two pieces used here are white oak and Brazilian cherry. Both are very hard woods, which will take strikes well in practice.
Step 4: Gluing it up
Clamp the center first, then work your way outwards. Clamp directly over all the support sticks, and then at the ends. Fill in clamps afterwards. Let the set-up dry for about 4 hours. Wipe off what glue you can. Once dry, scrape off the glue that has pushed out.