After marking the sawtooth tread-and-riser pattern on a 2x12, the author aligned a mounting bracket and tread block with the bottom edge of the template at each tread location.
Nest, he marked and drilled pilot holes for the mounting screws. At the base, he had to adjust the layout to account for the height of the mounting hardware.
Before making any cuts in the expensive 4x12 stock, the author checked the fit of the template.
The author used the template as a pattern to lay out and cut the 4x12 stringers.
Easing all the edges of the stringers with a 1/4-inch-diameter roundover bit gave them a more finished look.
Applying wood preservative on all surfaces with a roller helps protect the stringers and gives them a uniform color.
The author clamped the template to each stringer and used it as a guide to drill pilot holes for the mounting brackets.
The brackets were fastened to the stringers with 3/8-inch-diameter lag screws.