So I attempted to locate a pattern for this simple easy to wear clothing. First I searched my own patterns, and nothing worked, after several tries. Then it dawned on me that I should think of these shapes as sleepwear and found the needed shape in family pajamas. McCall's M5992.
I didn't want a collar or that length, but did want patch pockets at the bottom, and shirttail hem with slits. Other than that, this is the perfect pattern. Only I bought it in Large first and having made a sample shirt, discovered I needed Medium, so back to Joann's I went. McCall's patterns were on sale for $1.99, so haste was an issue.
Here's my finished prototype. Linen/rayon blend, ancient, with a scoop neck and much shorter sleeves that roll up. Rounded patch pockets echo the rounded hem.
Of course I tried to take photos of myself in the mirror, always a tricky task.
I am so happy to have devised the pattern to suit my needs. Loose fitting, covering the necessary parts, and plain enough to dress up with a fancy necklace or scarf, or just wear with leggings.
Now I will endeavor to add new features to this basic shape. I can pull this shirt over my head without undoing the buttons, so a dress is in the offing. A yoke at the shoulders, with a pleat in the back, multiple fabrics, and a shorter or longer version too.
It occurs to me that I will begin by using some 'quilt' fabric, and rid myself of a tiny bit of pressure to use it all up.