Now the most authoritative part, which can be called the brainstorming part of action. Make a through plan of action, study as many books and literatures available on simple robot making, make some notes of those and try to memorize and summarize those parts. Then you can learn the various methods that is the systematic way of building the robots body parts. Then you can learn about the various logics and analyze the inference and try to make an idea in a methodical sense. Then you can learn about designing part of the circuits. All these parts written above can be called brainstorming; it is an significant part and needs to be done thoroughly and sincerely.
Ponder upon available resources and derive and design the best way to exercise and utilize those resources in full capacity. These include the design of body parts of robot, the coding part and the circuit design. In a sense the mechanical, electrical and the coding part of robot. Then comes the structural part, the building and assembly stage of the project. The assembly part consists of a group of machine parts that fit together to form a self-contained unit that is the robot. After going through all these steps analytically and theoretically , you need to check again each and every steps so that you cannot miss anything in between and you have done each and every steps according to yours logic and to the brainstorming part.
A word of caution, if you do not follow the sequential approach as suggested above, the approach in regular succession without gaps then you will face in the later stages some tedious obstacles. So it is better to work in a sequential periodical systematic manner.