So I finally got round to attempting my SmartApp to send hub events to my local server. The combination of forum discussion and the documentation made me wonder whether it was even possible, and in writing the app I’ve learnt some things that might be useful.
I’ve blogged a few of my tips here, and I hope it might be useful to anyone else starting out. Most of it comes under “obvious when you know how” but hopefully there’ll be something useful there for other beginners.
Or you can just chuckle at the thought of me running up and down to the front door until Tip 2 struck me 
Edit: got part 2 up a bit quicker than expected