Reference: Adidas AEROREADY sport shorts

Trousers block: loosely based on knowles.
Fabric: Woven, polyester
Detailing: Elasticated waistband casing, side pocket with zipper, style lines.
Comment: I did not include step on how to detail the waistband because I mainly deals on draft. Besides, this video by @MyDressPatterns already explain how to do it way better than I can. Though my version is different because I manipulate shrinkage weft of inner band instead of elastic lines. I also fake the tiny folds with many internal lines sewn together between outer and inner band.