R, the scope of your question is too broad to be answered here. For instance the design parameters for a locked down model are vastly different than those of an auto surface model. If you want to design a model from scratch you should first determine which class you want to compete in and develop a good understanding of the parameters of the class, rules, available power ect. Then study the designs that are proven winners and compile benchmarks that define their success. Last but not least apply your creativity to create a better mouse trap.