As lay people with a very specific and important vocation (See Decree on the Apostolate of The Laity
here ), I think to wear a religious habit when one is indeed a lay person can create a false impression to others that one is a religious or priest and a different vocation entirely. We are called as lay people to be
leaven within the mix, not called out of secular life into religious life or the priesthood. Called out of secular life into another state in life is identified by religious habit or some sort of priestly apparel.
The Decree on the Apostolate of The Laity is a very important document for lay people to become very familiar with and to internalize.
One can certainly adopt a standard type of dress that does not resemble the religious habit nor any sort of priestly garb. St Gemma Galgani did this - although what she did wear was very close to a religious habit but still not a religious habit per se. I think it is very important that somehow we can be identified in society as Catholics and primarily this will be, of course, by the person that we are. If we do identify ourselves somehow as Catholics by some sort of apparel - it then becomes of vital importance that we realize we have set the bar very high for ourselves and with a responsibility and accountability before The Lord to strive to live up to what we are ‘stating’.
I always wear black slacks and with a very simple cross on a leather thong. I wear a commitment silver band on my wedding finger. Black slacks means that I can do all my shopping for clothing in second hand stores keeping things simple (I only really need to buy tops) and marked by a certain poverty for me. Nowadays, clothing that is purchased in a second hand store at least here in South Australia is very cheap indeed and of excellent standard - yet still ‘pre-loved’ or pre-used. Black slacks here are not difficult to locate and to buy in second hand stores.
It did take me quite some time to identify and develop a type of apparel that would be suitable for all occasions and cheap to purchase. Here in Australia, black slacks with some kind of top are quite acceptable at all and any venue. Leastways, I have never had problems and I have been able to purchase second-hand tops that are more formal for more formal occasions. I never take off my cross nor commitment ring and wear no other jewellery unless going to something really formal when I might add earrings and necklace, with the cross on thong still, sometimes a bit of makeup.
I am very conscious that I am a mother with two adult sons and in Charity, the presentation of their mother is important to them - and I would add, important to me also as their mother.