From my experience, I will start with a big picture, defining functionalities, interfaces, components, etc. Drafting a state machine diagram to have an idea what areas need to be developed.
Then, usually using a framework (for example Queue Message Handler/Producer Consumer) to create a prototype, to test the logic, in parallel I begin getting the components to make use of the program, for ex Daq, instrument, graphic analysis, Storage, DB).
One thing that always help to start with is to create a "Manual Mode" for ex if your system involves daq, instrument, can, etc, you make one single vi that contains all the components, so you can learn how to interface with every component of your code, and they run in parallel all together. WIth this, helps you plan to develop the routines that will be used in your final application, understandin APIs, etc.
Then define the subvis, routines, find patterns that can be packages as sub-routines.
Then pack everything together and test . Voi-la.
When start programing right away withtout any planning usually leads to spagetty code, that is hard to mantain, difficult to replicate and troubleshoot becomes a nighmare.
