This is how we will lay out a Stringer for the mini bathroom. The strength of the wood is with the grain and so we lay it out diagonally using a 45° angle consistently.
Start with 1-1/2" wide piece, and put a 45° angle from the corner.
The first line that we need to make is the Run for the top step. Make sure when lining up the 45° angle account that it is not starting at zero. I believe it was about an 1/8" on this Square.
We will lay out where the cutout is for the header. Again make sure you are putting out a 45° and account for the length and width of it.
Next we are just laying out the rise and run for each stair. Note that I put a number next to make sure that I went the correct number of steps.
Cut everything out on the bandsaw.
Safety:
Cut slow and make sure to hold on to the piece so that your hand is never going directly at the blade.
Find a piece of scrap wood and clamp your Stringer onto it. Trace it.
When cutting out make sure to cut on the line a bit because tracing is bigger than the actual.
Get the pieces for the header, bottom plate, and treads and use a miter gauge with the fence set to the correct width and cut them.