Most developers that I know of that have been using OO languages for some time, including myself, also usually start with the data items being dealt with and pr

Most developers that I know of that have been using OO languages for some time, including myself, also usually start with the data items being dealt with and proceed from there. In fact, it's not particularly natural to do it any other way. If you've got a window, then it's a Window class, with all of the relevant behaviors (methods) added afterwards. If you're dealing with a file, then it's a File class, and so on.