The most important point is structure , If the structure can be simplified as much as possible, but the quality of the mold must be guaranteed, the company will earn the maximum profit from it . 
When we received a product , the first question is find out the biggest parting surface , Roughly determine the cavity and the core , then , To Analyze the construction of cavity and core , insert , slide , lifter etc. After decided the structure of product , next we need think about the mould processing, thereby make sure rationality of the structure : add insert or not ? Should use CNC mechine or just wire cutting ? or sculpture ? And other processing technic. 
Structure of the mold will influence mould processing  , and it will be an important factor to decide the cost and delivery time .