How can I add the accessory to an item that's already an accessory?

If you have a chair that requires a color of cushion to be added to it, and the cushions sometimes require a clip to be added, you can first set these items up as accessories in your inventory (learn more).

Then, on your projects, you'll be able to select the accessories to go along with each item by clicking the 'Related Items' button next to the item name, or see the required accessories automatically add.