A Women's Garment Must Have Certain Characteristics:
First: It must be ample and not tight.
Second: It must be all-encompassing, covering her entire body and not letting any part of it show - not the hands, the feet or any part of the face. It must cover entire body.
Third: There must be no decoration or adornment in it. So it must be a casual dress containing no decoration, which would draw looks towards it. A muslim woman must beware of what the Messenger of Allaah (sallaallaahu alayhi was sallaam) said:
"There are two types of people from the dwellers of the Fire that I have never seen before, (the first is) women who will be clothed yet naked, inclined (towards disobeying Allaah) and inclining others, their heads will be like the slanted humps of the bukht camel. They will not enter Paradise, nor will they perceive its odor even though its odor can be perceived from a distance of such and such."
(Reported by Imaam Ahmad (2/356) and Saheeh Muslim #2128 from the narration of Abu Hurairah)
Taken from Four Essays on the Obligation of Veiling, 3rd Treatise "Advice to the Muslim Women" - By Shaykh Saalih ibn Fawzaan Al-Fawzaan pg.70)
May Allaah make us from those who smell the fragrance of Paradise and enter us into to it, and grant us protection from the Hellfire. Aameen.
Sisters Upon Al-Istiqaamah