Zero diopter reset

When introducing a reduction it is not advised to just slap them on your face, as the visual cortex associate the change with lowered clarity, which is bad. You want to start with lower correction before introducing the reduction, which makes the visual cortex associate it with increased clarity.

Normalized

As a rule, you never want to wear your new lower normalized on the same day after wearing your full correction or previous normalized correction.

What you do is take a day you can manage with no correction (or differentials in the case of high myopia) from the beginning of the day for as long as reasonably possible, until you start to feel uncomfortable. This way when you introduce your new normalized the relative standard for expected clarity is that things are much clearer and this is a good change. The good association with your new correction is a big advantage.

Differentials

If you already wore the previous differentials, do not wear the new differentials until the next day.

References

Hear it from Jake: https://www.youtube.com/watch?v=zzrQb4pCFkQ