Decimating and Smoothing

[theFinn01]

Is there a preference between the order of these operations? I feel like you would smooth the high-face model first, then decimate the smoothed model... but I also have no idea what I'm doing.

[Bzuco]

There is no order of these operations, because they are unrelated.
Smooth the model make sense only if you have some unwanted noise on the surface(e.g. caused by high camera ISO) or you want to suppress some elevation differences(spikes) on model for some reason.
Purpose of decimating the model is to achieve the original model shape with as low as possible polygon count.

[theFinn01]

I guess the "achieve the original model shape" is the point that I was using as the baseline reasoning for doing the smoothing first - iron out the imperfections, and then decimate that smoothed model.