Maintenance for the week of January 12:
• PC/Mac: No maintenance – January 12
• ESO Store and Account System for maintenance – January 13, 9:00AM EST (14:00 UTC) - 12:00PM EST (17:00 UTC)
Also, you will need to make sure that you have enough traits researched PER PIECE that you want to craft. Once you have the right number of traits unlocked, then just go to these crafting locations, and go to the crafting tables there. They will have the normal options for crafting, but they will also have option for crafting the sets. Make sure you use the right tab to craft the set.
Other than that, it's just like any other crafting. You use the materials you want to craft the level/style/trait of your choice, and as long as you are in the right crafting tab, it will create the armor/weapon of that set.