Drawing 0. Choose a scale, Draw the total run and the total rise on your square paper. On this example, the total rise and total run are equal, therefore the angle of elevation of the staircase is 45°.
Drawing 1. Decide how many steps you want to include. Divide the total rise and the total run into this number to see how high each step is and how long each tread is. Mark points to show the steps.
Drawing 2. Draw a line through the upper points to show one edge of the board the stringer will be cut from.
Drawing 3. Given the board is 8 inches wide (or some other width), calculate where the other edge of the board will be. This requires some math.
Drawing 4. Now you're ready to outline the stringer and shade in.
Drawing 5. Square off the ends of the board and calculate how long a board is required for this stringer.