It happened that I switched jobs at the end of August. Upon hearing that this was about to happen, a friend pinged me and asked whether he could hire my services for "one to two hours per week". I rejected the offer. I specifically told my friend that "one hour per week is a trap":
A week is 168 hours. You sleep 56 of them, so let’s say that you have to give 1 hour out of 112. To be more precise, 1 hour out of 72 you can spare. Surely you can allow yourself 1 hour of a side-gig, right? But then it is Monday. And you start your working day, and "oh, I’ll deal with this tomorrow" and this goes on until Friday and you say, "I’ll do it Saturday morning before the other chores". And you squeeze that hour somewhat grudgingly, between Saturday and Sunday night.
If I’m wrong, why are then all those Udemy / whatever vocational courses you’ve purchased unfinished? Did interest wane down on all of them right after the first couple of hours?
So say no to "one hour per week engagements". You’re setting up yourself for frustration and failure.
As for me, I’ve arranged for virtual coffee with my friend once per month to discuss his vision and progress. Because everyone needs someone to talk to.
Managing organized complexity 
Dunno…. I think 1hr per week is simply too much time, that’s the only issue. Perhaps 2hrs every two months would work though. Most people think I’m kidding and that this just means you don’t do the task, but I’m not. I see that exactly because of “all these Udemy courses…” etc. etc. plus other personal projects. I didn’t expect that when I was younger, but I see that they *do* get finished. It just takes *years*. If you asked me when I was in my late 20s, if something you ‘ve been putting off or working on and off on, which is in total e.g. 2 months of work (things like building some handywork, finishing a course, creating an app whatever), if you haven’t finished it 2 years later, is it ever going to get finished or not? I would say no. Now, in my 40s, having finished several of 2-3 month projects in 2-5 (!) years each, I can say “yes, if you had a long enough life, you’d finish it” :)
So if this friend told me “you’ll work for me for one day every 4 months” perhaps I’d do it.