I have already met with many crypto-currency exchanges, with very popular and not very popular than you are better than others in this field?
Each exchange has its own characteristics, but I believe that it is necessary to pay attention to the technical functionality of the platform - first of all.
Technical characteristics and how this exchange will work are the most important things about exchanges. I think that first of all everyone should get acquainted with the White Paper. Usually all the necessary information is written there.