Step 2:

I cut 2 pieces of C-hanger to about 6" and 2 more about 4 "
this is not Rocket Science so it approximate

****WARNING**** Always wear safety glasses

Bend the angles as shown in the drawing, I just went with comfortable width of the pliers.

Bend about 1" at the bottom and loop around the pliers (or use philips screwdriver)

I drilled four holes for the screws in the cornners of my scrap O wood
I think i used #10 screws and screw them into da holes.

The C hanger is quite flexible and will adapt to most size boards. Make different size boards and add a few more C hanger to hold up.
it held well and is pretty sturdy