Here are a few ideas:
Enable ‘oversubscription’ for your event; this allows pledges to exceed your goals. You can access event oversubscription settings by clicking once on the event code for your event ID and selecting Edit Event from the Event Options menu. Click the “?” for an explanation of how each setting impacts pledging.
Canned food, utensils, crayons, etc… are fairly common catch all type items that you can use to supplement your registry.
Think bigger! Increase your item goals, and see what happens!