1) Define the problem that you want to solve with your program. What are you trying to accomplish? What inputs will be required? What outputs do you expect? This step is important because it will help guide your design decisions later on.
2) Design the algorithms that will solve the problem. This step includes figuring out how the data should be processed and what steps need to be taken in order to achieve the desired outputs. The algorithms should be designed in such a way that they can be implemented by a computer.
3) Write code in a programming language that implements the algorithms from step 2. This code will serve as instructions for telling the computer what to do when it executes your program. The programming language you choose will depend on various factors such as which platforms (operating systems) you want your program to run on and which features you need access to.