I've just finished writing an instruction sheet, for my IoT students, on how to control NeoPixel strips.
Note: This exercise uses a WeMos D1 Mini, Node-RED and MQTT (mosquitto) and of course a NeoPixel strip.
I hope you enjoy reading this as much as I enjoyed writing it.
Regards from David.
PS: The document, in the above link, has been updated to implement the comments from various people.