I just found pictures one of my 6 constant current high power LED dimmer boards I build for my garden (as mentioned above).
powered by a 24V power supply (the transformer is inside a shed). You see the step down buck converter, a smoothing capacitor (think useless as the ripple I expected would better be smoothed by a small ceramic capacitor instead an electrolytic). 6 cc LED drivers (1-2W) with available enable PIN for PWM dimming. All berried under a foodbrige (this is where a good AP pays). Never had any issues (Even in this noisy environment of 6 dimmers and a switching buck converter)
So nothing fancy. (BTW: One downside of the ESP8266s. They come with now hardware timers for PWM signals. PWMs are generated in software! So keep the frequency down and expect some glitches. Nothing to be worried but good to know)
Not the best picture:
