Our cotton leaves the floor pre-shrunk, but the first wash still sets the character of the fabric. Three decisions matter.
Temperature: 30°C is enough. Detergent: half of what the box says, because excess does not rinse out and dulls colour. Spin: shorter and slower — most fabric damage happens in the spin, not the wash.
Skip fabric softener entirely. It deposits a waxy layer that reduces breathability — precisely the property you paid for.
Line dry in shade. Cotton that dries slowly stays softer, and shade protects the dye.