Stain all of the wood, then allow time to dry.
On both 1x3 boards cut to 72” long, mark as shown in the diagram with a pencil.
Space a rung up on a scrap piece of 1x3 board, supporting both ends. Clamp the rung to your worksurface. For beginners, predrilling is recommended but not required. Attach with top edge on inside leg mark, with two screws.
Repeat steps to attach remaining rungs to first leg.
Attach remaining leg to all rungs, using the spacer block to elevate each rung as you screw through the leg into the end of the rungs.