Black Hoodie is the most common "A" disguise, worn by almost all of the "A-Team" members. Mona Vanderwaal originated the hoodie disguise and it was later used by Charlotte DiLaurentis and the "A-Team". The disguise consists of a black hoodie, sometimes a black mask, and black pants and shoes.
The Zombie Stalker costume is a disguise worn by Mona Vanderwaal to attack and spy on Alison DiLaurentis on Halloween of 2008. It was "A's" first known disguise and was meant to resemble a baby zombie with burlap clothing. Charlotte DiLaurentis donned only the mask to hide from Hanna and Spencer and various other people have worn the costume, though seemingly not related to "A".
The Black Swan
The Black Swan is a disguise worn by Melissa Hastings to attend the Masquerade Ball and distract Jenna, on "A's" orders. The disguise was meant to resemble Odile from "Swan Lake", though appeared a lot like the one Natalie Portman wore in the film of the same name.
Red Coat is a disguise worn by Charlotte DiLaurentis and Sara Harvey. The disguise consists of a red trench coat, similar to Vivian Darkbloom's, and an Alison mask to conceal her identity to her followers and the Liars. Charlotte wore the disguise as the leader of "A-Team", while Sara was a decoy. However, after Alison and Charlotte were discovered, the disguise became only Sara's.
The Queen of Hearts
The Queen of Hearts costume is a disguise worn by Melissa Hastings and Darren Wilden aboard the Halloween Train. The costume is based on the Queen of Hearts and was worn to carry out "A's" orders, while concealing their identity.
The Black Veil
The Ali Costume
The Ali Costume is a disguise worn by a female member of the "A-Team" to trick the Liars at the Ambroise Pavilion Zoo. It is based on the clothing Alison wore in Season 4b. It's presumed to be Sara Harvey or Charlotte DiLaurentis.