1.No "using namespace std;" 2.Clearly declare "private" inside of class. For example: use class item{ private: int price; public: getPrice(); } instead of class item{ int price public: getprice(); } 3.Declare inheritance type(public, private, protected) when using inheritance. 4.If not finished with code, add a TODO as comments. 5.Add comments to explain what you want to do.