Here we go again - time, budget, workflow.
Unless you are working at Skywalker Sound, Todd AO or a similar facility everything is at the discretion of the Supervising Sound Editor; and even each of those major facilities will have its own workflow.
Time and budget dictate the workflow. The more time you have and the bigger the budget the more flexibility you have. On a $100 million film the audio editing is handled by all of the specialists, overseen by their department heads who are in turn overseen by the Supervising Sound Editor. With the exception of some sound FX no premixes or treatments of any kind are done prior to the final mix, although preliminary presets for NR, EQ, reverbs, etc. may have been created. This gives the Rerecording Mixers absolute and final control over the minutest details of the mix. What you have to keep in mind is that the department heads, Supervising Sound Editor and Rerecording Mixers generally have long standing relationships, so the workflow is almost second nature. Much also depends upon the nature of the film; there is a huge difference between doing a film like "Avatar" and "She's Out of My League", the workflow will be vastly different as will the size of the audio post team. (Just for fun, "Avatar" did premix some material as some parts of the final mix exceeded the 1,000 track capability of the mixing facility.)
At my level I am - for the most part - a one man band; I do it all on my own working on severely restricted budgets. This dictates my personal work flow. I do a lot of preliminary mixing as I go but don't commit myself to anything except perhaps noise reduction. The reason is that many of my clients have little or no experience with the audio post process and lack the experience to imagine what things will sound like later. I often disable the temp EQ and effects for their first listen, then reactivate them for the second listen so they have some idea of what the finished mix will sound like; they need the reassurance and, to be honest, so do I.
