I've not used a FSM before either, but I got one up and running a motion lighting flow. Once you've got the idea of transitions and states the method becomes clearer. Much easier than a complex RM app IMO.
Uses node-red-contrib-state-machine (node) - Node-RED. Flow based on https://www.reddit.com/r/homeassistant/comments/afk6cd/building_smarter_motion_lighting_nodered_finite/
