The more experience I have the more I answer every question with "it's complicated, it depends". On top of that, everyday I am more convinced that methodologies are as vital as they are useless. I know, it seems non-sensical sense but that's life and design, contradictory. Here is a list of essential very important methodologies I do my best to follow.
← Be aware of this if you want (and can) move up the chain. Most likely you are not going to redesign the business model but you might and have valid criticism.
← This sounds great to un-convinced clients who lived under a rock for the last ten years. In practice, take this as an aspirational model and do what you can. It's fine to go with your gut having enough experience, talent and willingness to listen to evidence in the future.
← You are not designing a full business in one go but keep an eye on the big picture to do really good work. Be aware and be humble... or set your aim high? both? Be wise.