The answer to this question is not as simple as it looks like.
There are lot of factors, some of the main factor that are required to be considered are the following:-
Amount of Capital you want to invest.
Demand and Supply.
Availability of Raw material and Labor
Location, as cost vary a lot at different locations.
Size of business one want to open.
Then it comes to which verities do you want to serve.
How trained and experience staff you hire.
How much you want to spend on outlook of you location.