To create a Set, follow these simple instructions:
Upload all single items you want in your Set, complete with an image, description etc.
Go to the Uploads tab and select all items you want in your Set (use the checkboxes on the right) and submit them.
Go to the Pending tab and select your Set items and choose "Create Set from Selected" at the bottom of the page
Edit your Set with an image, description, categories etc and save to submit it
Your Set has now been submitted and can be found under the Pending tab.