Begin by reading the care label: many sequin pieces are dry clean only. If the label says it can be machine-washed, turn it inside out, put it in a laundry bag and wash on a gentle, cold cycle with mild detergent. Alternatively, spot clean or give it a light hand wash. Sequin garments may not always need a wash, sometimes you can simply freshen them up with an airing.
Spread your sequin piece out flat on a towel and air dry. Do not use a tumble dryer as the sequins could melt or come loose.
Avoid hanging your sequin pieces as this can damage their shape. Instead, fold them inside out and put them in a mesh bag before storing them away.