How do you get size/ color drop selections on a listing?

[MountainGoth]

I see some listings have selectors where you can choose a color or a size. I do not see where you set these up in a new listing.

Can someone please point me to where you set these up.

Thanks,

Suzanne

[KatGurumi]

Join this prototype http://www.etsy.com/teams/12471/listing-variations

[MountainGoth]

Thanks!