We're released many different types of clothing collectibles, all of which can be used in Habbo X. You can buy these items directly from Immutable's marketplace.
1. To use them, you need to click on the Looks button on the right hand side of the UI:
2. Once you've opened the Looks Editor, you can select clothing collectibles that you own by browsing through each of the tabs, selecting items to wear, and then clicking "Save".