(written from a Production point of view)
Kacy Treadway is a specialty costumer who worked on 2009's Star Trek and will, according to IMDb, also work on the Star Trek Into Darkness. On the first film she worked between November 2007 and April 2008 and was responsible for creating the Keenser costume for actor Deep Roy. 
Treadway worked as specialty costumer on the television comedy The History of White People in America (1985), the science fiction comedy Amazon Women on the Moon (1987), the television series In Living Color, the comic adaptation Batman Forever (1995) and its sequel Batman & Robin (1997), the science fiction drama The Postman (1997), the comedy Like Mike (2002), the fantasy adventure Dr. Seuss' The Cat in the Hat (2003), the adventure Master and Commander: The Far Side of the World (2003), the comic adaptation Constantine (2005), Bryan Singer's remake Superman Returns (2006), and the fantasy film The Last Airbender (2010).
More recently, she worked on 20th Century Fox's Raising Hope (2010) and Paramount Pictures' The Fresh Beat Band (2011).