Modesty is the main requirement in Islam. For that purpose, I don't think it's wrong to wear suitable clothing other than jilbab.
Said who? You and I can not interrupt the Quran'c verses we have have to understand it according how the Prophet (sal-Allaahu 'alayhe wa sallam) undertood it and the best of generation, the Companions (radhi-Allaahu 'anhum).
Did you read the link I posted? In case you missed it out here it is once more:
http://www.islamicboard.com/islamic-jurisprudence/23274-jilbaab-what-garments-can-substitute.html
All I am saying is if a sister newly started practsing then she can work on herslef, step by step by wearing garments that will lead her to the correct Hijab, i.e Jilbab starting from the head going down covering the entire body.
The requirements of hijab are never oppressive or restrictive in any way; here are the requisites of hijab or proper Islamic attire for women:
1. It should cover her whole body except face and hands.
2. It should be loose-fitting.
3. It should not be transparent or revealing.
4. It should not be an attire specifically worn by men only.
Yes, those are some of the requirements of hijab and most sisters are aware of it, however where do you draw the line? A sister will tell you, my skirt is mosdest enough, and another would say no, its too tight, a third would say Saris is more modest and a fourth sister would say it is not required to cover the feet.
Who is our best example here? Is it not the Sahabiyyat? I am sure they were from every corner of the earth, yet they wore one Hijab, the one commanded to them and us by Allah
Yes sure we can wear skirts, trouse, saris, etc but in our homes, amongest just women, but when it comes to going outside of your houses, then we should pull up our Jilbabs.
Narrated Umm Salamah, Ummul Mu'minin when the verse
"That they should cast their outer garments over their persons" was revealed, the women of Ansar came out as if they had crows over their heads by wearing outer garments.
[Abu Dawud]
'Aisha used to say: "When (the Verse):
'They should draw their veils over their necks and bosoms,' was revealed, (the ladies) cut their waist sheets at the edges and covered their faces with the cut pieces."
[Bukhari]