Original skins created in the Skin Editor can be equipped on your own player character.
Open the Shop Screen from the Channel Lobby while the skin you created is shown on the Skin Editor Screen.

Buy "Add Original Skin" in the "Special" category.

The skin data currently being retained will appear.
Choose a savable skin slot from below and click the "OK" button.

You can now equip the skin you purchased in the Edit Character Screen.