No matter what you do daily or love to do, it could be cooking, cleaning the house or even shopping, everyone has their own personal way of style in doing that. There is no specific way of what you need to do first before cooking. Some people will cut vegetables first before the meat and even the cutting style is not the same with everyone. There is no specific things to clean first in the house. Some would start wiping the chair first instead of the television. Some would even clean the table first before washing the dishes but some would do the other way around.
It does not matter what we do first but we will still get the same end result. I am stating all this is because of what I am doing daily at my job, coding. There is no fix way of how you want to start building your product through coding. It could be an app or even a website, but the way you code will not be the same with everyone. Well, there are some good practice method that can be found online and some would follow that but some would still stick to their own method.
For instance, I love make sure that all my codes are reusable and dynamic from the start. I will go the extend to always separate my codes into a modular component where I would then plug and play it in another component or pages without doing the 'Copy & Paste' method. By doing it this way, it will be a slow pace in the beginning but during any debugging mode, that is where doing reusable components shines. I will just need to change one part of the code and everywhere will be updated accordingly.
In the end, there is no wrong in whatever method that you will do your things. All it matters is that it still gets the job done with the same outcome.