Fashion Police Achievement
Any Hero wearing a complete armor set for the first time.
Find or trade for the set pieces randomly dropped by enemeis (hard part), and equip all of them at once. Try wearing items that have the mod, "Chance to find valuables +X%", to have a better chance to find the set items. Also, the skill, "Enhanced Pereception", will increase you chance to find valuables by a good amount as well. Also a full set consisting of 2 rings can also be used to obtain the achievement much easily:
Get "Benny's ring" from a quest - then do the 89 ascaron employees quest, which will give you another ring. These two rings form a set, and you will get the achievement (better than waiting for a random drop)