I don't have many, but I'll share my most used one:

My lamps and overhead lights are all smart bulbs. I've got several different modes (lamps only, overhead only, all lights, etc) and can control them with a unified dimmer.

The problem I had at first was that the overhead lights overwhelmed the lamps, and everything was too bright. So I added a step to the dimmer control to set the overheads to 75% of the dimmer value while keeping the lamps 1:1. Works great. I can even toggle that on and off.

Using HomeAssistant with all the logic in NodeRED.