Templates is the only way I work - ensures efficiency and reliability. I honestly can't begin to think of not working with them, especially for large feature film layouts. I have various templates (DX, ADR, Foley, FX, BGz, Sub/Stem/PM layouts, etc), and some templates from studios I've worked with where the mixer has provided what they like to use and expect to see in a stage delivery - so on shows with those studios, I use their provided templates. When I crew up with other people on a show I'm supervising, I give out a template to my editors which I'd like for them to use on the show. Usually all these templates are just tracks, coloring, and naming - in some template cases, additionally bussing and and aux assignments are part of it. Everything else though remains blank. For plugins, I just know my go-to's and have made presets of them for certain things so I can quickly build a signal chain on the fly and tweak from there.
You're right, every scenario is different. Yet in my experience, I've found the variety to be not very much (at least for doing post sound), and in many cases you can easily conform a shows needs to fit within one of a few templates.
On some cases I'll tweak a copy of the layout I make to use for a show, because you may have a show where for instance your BG layout it fine, but there's so much water/beach in the film, it's nice to have a dedicated 8 tracks for waves (versus water/ocean tones). In these kinds of cases, I make a tweak o the layout only for the specific show in question. But I always begin from a set of core templates and extrapolate from there if and when necessary - usually everything fits within the original template construct in my experience.
