Sharpen a Shoulder Plane
If it's a bevel up plane and it's in my shop, it's going to get sharpened to 40 degrees and the back of the blade is going to get the ruler trick.
My shoulder plane is no exception. But, because it's a joinery plane, I make a little extra effort to make sure the edge is square to the sides.
Here's a video with a little intro to the shoulder plane, a look at my sharpening process, and how I dial the blade back in after sharpening.