I made a draw knife a few years back.
It is only small (4 inch cutting edge), as I would have struggled to heat treat a bigger one with the facilities I have at home (only a blowtorch). It is made from an old leaf spring, and the hardest thing was getting it flat. I think I would use ground flat stock if I was making another. The blade was rough shaped and bevelled with an angle grinder. The tangs were cut out in line with the blade, and bent around afterwards with a bit of heat.
The grind angles are about the same as a wood chisel (25 degree primary, 30 degree secondary), and the heat treatment is on the soft side (more brown colour than gold or straw), as sometimes I rock the blade in a cut to break away a lot of waste, and I don't want the blade too brittle for that sort of use.
It is not a thing of great beauty, and has no pretensions to professional fit and finish, but it works and gives me great satisfaction to use it.
Hope this helps.