The proper way to wear a Talit is to drape it such that two Tzitzit strings are positioned in front, and two in the back, behind the individual, so that he is surrounded by Tzitzit on all four corners. The practice of some people to wear the Talit like a scarf, with all four Tzitzit strings hanging in front of the person, is incorrect.
The question arises, must the same two Tzitzit strings be positioned in front, and the same two in back, every day? Must one ensure to always wear the Talit with the same side in front and the same side behind, or may the Talit be positioned differently from one day to the next?
Some Poskim (authorities of Halacha) prove that one must wear the Talit the same way each day from a comment in the Talmud Yerushalmi (Jerusalem Talmud) that the boards of the Mishkan (Tabernacle) were positioned in the same place each time it was erected. The reason, the Yerushalmi explains, is that the boards situated closer to the Aron (Ark) were of a higher level of sanctity, and it was thus forbidden to move them to a different location, as this would lower their status of Kedusha. Similarly, these Poskim argue, the Tzitzit strings in front of a person are of a higher stature than those behind him, and it is therefore forbidden to have them positioned in the back on a different day.
This ruling gave rise to the common practice of placing an Atara, an embroidered collar, along one side of the Tallit, so that the individual will always know which side is worn in front, and which side in back, resulting in a consistent day to day arrangement.
In truth, however, the Arizal (Rabbi Yitzchak Luria, legendary Kabbalist, Egypt-Tzefat, 16th century) did not make a point of ensuring that the Tzitzit strings were always positioned in the same way each day. This is, indeed, the final Halacha, that it is permissible to wear the Tallit with the sides reversed.
There is a practice that is found today, to embroider Pesukim or a Beracha on the Atara of the Talit. This is not proper. A Talit is an article used for a Mitzva ("Tashmish Mitzva"), but is not an article of sanctity (Tashmish Kedusha) like Tefillin. As such, it may, strictly speaking, be worn in the bathroom. If, however, a Pasuk or Beracha is embroidered on the Tallit, it obviously may not be worn in the bathroom. It is therefore proper not to have verses or blessings embroidered onto the collar of one’s Talit, lest he mistakenly walk into the bathroom while wearing the Talit.
In summary, one need not, strictly speaking, make a point of positioning the Tzitzit the same way each day, despite the widespread practice of embroidering a collar onto the Tallit to ensure that the same side will always be in front. One should not have Pesukim or the like embroidered onto the collar of the Tallit.