Architectural marvels exist in pants, too. These are from the Pleats Please Thicker Bottoms series, which have a little more heft to the textile. In turn, they allow for a variety of angles and directions to hold together well. Elastic waist, side pockets.
NB on sizing: Pleats Please sizing is inherently flexible due to the nature of the fabric, which stretches generously. The primary difference between sizing is in length.