Islamic Dress Code for Females
Question

Being a Muslim woman, how must they wear their attire to say that she is a Muslim woman?
Praise be to Allah.Scholars have specified the requirements of the Muslim-woman's proper dress before al-ajanib (lit. foreigners, i.e., those to whom marriage is permissible) from both the Glorious Quran and the Sunnah. 
Once a woman adheres to such conditions, she can wear whatever she likes and go out into public places so long as her hijab complies with the Islamic law. 
A summary of the requirements of the Islamic dress code for females is as follows:

It should cover the whole body.
It should be thick enough, i.e. non-transparent or translucent.
It should be loose and not tight on her body.
It should not be decorated or ornate such as to attract onlookers.
It should not be perfumed.
It should not be considered libas al-shuhrah.
It should not resemble the dress of men.
It should not resemble the dress of the unbelievers.
It should not bear crosses or depictions of anything with a soul (humans, animals, etc.)

This is a summary of the requirements of the Islamic dress code for women according to the Islamic Shari'ah. 
For more, please see these answers: 7436 , 13245 , 114050 , and 20475 .
And Allah knows best.