Remove pins or buckles, zip zippers, close snaps and hooks, and secure Velcro to prevent snags and abrasion. But don't button buttons, which can stress the buttons and buttonholes.
Empty pockets and turn them inside out, unfurl socks, and unroll cuffs. Tie sashes and strings to prevent tangling. Place delicate items like lingerie and fine knitwear in zippered mesh bags. Turn delicate items, sweaters, and cotton T-shirts inside out to prevent pilling. Put socks—oh, those socks—in a pillowcase or mesh bag so they don't get separated.