ux designer – What are the best approaches to a UX project?

I read that “a good designer knows that each project will need a uniquely considered approach and tools” and a bad designer will have “a cookie-cutter set of tools that they believe work for every project”.

My question is, how do you know what the best approach and tools are for each project?

I understand the different approaches you can take towards a project but from what I have found, there is very limited information discussing how you choose the best approach for right project.