Summarize this article:

Close the hook and loop fasteners on Velcro whenever you are not using it. This will protect the hooks from picking up stray matter like lint, hair, and other debris. Velcro is designed to be sticky and will easily grab onto things like blankets or clothes from which it will pick up lint. When you wash Velcro it will pick up lint, hair, and anything else floating around in the washing machine. Keep the hook and loop fasteners closed when you wash Velcro to keep this from happening. Wash garments that contain Velcro separately from other items when possible. Washers and dryers are full of lint that Velcro attracts. Leave garments that contain Velcro to air dry so the Velcro doesn't pick up lint from other clothing and fabric items. If air drying isn't possible, then keep the Velcro tabs closed and dry the garments in the dryer separately from other items.

Summary:
Keep Velcro tabs closed as much as possible so they don’t collect debris. Close Velcro tabs on garments before washing them. Let Velcro air dry instead of putting it in the dryer.