Woodcraft sells a simple Ulu knife kit. A while back, I picked up five of them because they were on sale for something like half off. Not much to these. Just a blade and some optional rivets. The only mildly difficult part is creating the tiny little mortises where the handle will sit.

I neglected to take a photo when creating the 3/64" deep mortises, but it's pretty easy to do with a tiny chisel. I could have used a tiny router plane. Someday, I may pick up on of those.
After I rough cut the shape I wanted with a bow saw, I switched to my miracle files from Auriou (as I call them) to shape it well. These files are expensive because they are handmade in France. They are worth every penny.
Nothing fancy, but functional. This handle is from a scrap of bubinga. I made it extra thick and nicely rounded, as it was a gift for a person with large hands.