This is always an interesting question as it does not have a straight forward answer. I am in product development. Our projects can last from months to years depending on the product. Projects go through phases of concept to design, to prototype, to pilot production, to product launch. What we do on a daily basis is dependent on where we are in the product development cycle and the complexity of what we are trying to accomplish.
From a task standpoint, we review requirements, develop rough concepts, build proof of concept models, CAD, prototype, build, test, revise the design and retest, release parts for tooling review, revise the design, tool release drawings, review parts off of tools, make adjustments, assemble, test, qualify, support production builds. I am sure that I skipped several steps and it is a very generic description.
In short, we are always doing something different on a day to day basis and we are always learning.