First, close all the zippers. Yes, every single one. The front zipper, the pit zips, the pocket zippers. Why? Because a flapping zipper will destroy the fabric in the washing machine. It’s like putting jagged teeth inside a silk dress. Also, loosen all the drawstrings. You don’t want a tangled mess that looks like a spaghetti monster.
Next, check the pockets. Empty them. No, you cannot wash your granola bar wrappers, forgotten lip balm, or that lucky rock you picked up on a hike. The machine doesn’t appreciate your laundry day archaeology.