To use a steel square for creating precise corner spline joints, you would first measure and mark the desired location for the joint on the wood. Next, place the steel square on the marked corner and align it with the adjacent edges of the wood. Use a pencil or a knife to trace along the edge of the square, creating a precise guideline for the joint. Repeat this process on the other piece of wood that will be joined. This guideline will help you accurately cut and align the splines, ensuring a precise and snug fit for the joint.
